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Nano Energy (2013) 2, 636–676 Available online at www.sciencedirect.com journal homepage: www.elsevier.com/locate/nanoenergy REVIEW The development of mixture, alloy, and core-shell nanocatalysts with nanomaterial supports for energy conversion in low-temperature fuel cells Nguyen Viet Longa,b,c,d,e,h,n, Yong Yanga, Cao Minh Thif, Nguyen Van Minhh, Yanqin Caoa, Masayuki Nogamia,d,g a State Key Laboratory of High Performance Ceramics and Superfine Microstructure, Shanghai Institute of Ceramics, Chinese Academy of Science,1295, Dingxi Road, Shanghai 200050, China b Department of Molecular and Material Sciences, Interdisciplinary Graduate School of Engineering Sciences, Kyushu University, 6-1 Kasugakouen, Kasuga, Fukuoka 816-8580, Japan c Department of Education and Training, Posts and Telecommunications Institute of Technology, Nguyen Trai, Ha Dong, Hanoi, Vietnam d Department of Materials Science and Engineering, Nagoya Institute of Technology, Gokiso-cho, Showa-ku, Nagoya 466-8555, Japan e Laboratory for Nanotechnology, Ho Chi Minh Vietnam National University, Linh Trung, Thu Duc, Ho Chi Minh, Vietnam f Ho Chi Minh City University of Technology, 144/24 Dien Bien Phu, Ward 25, Binh Thach, Ho Chi Minh City, Vietnam g Nagoya Industrial Science Research Institute, Yotsuya, Chikusa-ku, Nagoya 464-0819, Japan h Hanoi National University of Education, Vietnam Received 15 March 2013; received in revised form 16 May 2013; accepted June 2013 Available online 25 June 2013 KEYWORDS Abstract Alloy and core-shell nanoparticles; Pt-Pd core-shell nanostructure; Supports; Oxygen reduction reaction (ORR); Proton-exchange membrane fuel cell In this review, we present the development of Pt-based catalysts and the uses of Pt-based bimetallic and multi-metallic nanoparticles with mixture, alloy and core-shell structures for nanocatalysis, energy conversion, catalytic nanomaterials and fuel cells (FCs) The important roles of the structure, size, shape, and morphology of Pt and Pd nanoparticles, which can be engineered via chemistry and physics methods, are discussed To reduce the high costs of FCs, Pt-based mixture catalysts can be used with cheaper base metals Importantly, Pt-based alloy and core-shell catalysts with very thin Pt and Pt-Pd shells, Pt-noble-metal coatings or Pt-noblemetal skins can be used as Pt-based catalysts in FCs, typically low- and high-temperature n Corresponding author Tel.: +86 21 52414321; fax: 86 21 52414219; Mob.: +81(0)90 9930 9504; +84 (0)94 6293304 E-mail addresses: nguyenviet_long@yahoo.com, nguyenviet long01@gmail.com, nguyenvietlong01@yahoo.com (N.V Long), mnogami@mtj.biglobe.ne.jp (M Nogami) 2211-2855/$ - see front matter & 2013 Elsevier Ltd All rights reserved http://dx.doi.org/10.1016/j.nanoen.2013.06.001 The Development of Mixture, Alloy, and Core-Shell Nanocatalysts with Nanomaterial Supports for Energy Conversion (PEMFC); Direct methanol fuel cell (DMFC) 637 proton-exchange membrane FCs (PEMFCs) and direct methanol FCs (DMFCs) On the basis of the latest scientific reports and research results, new catalytic models of the possibilities and relations of both Pt-based catalysts and supports, which are typically carbon, glasses, oxides, ceramics, and composite nanosized nanomaterials, are proposed for the further investigation of catalytic surface roles to achieve crucial improvements of Pt-based catalysts The various applications of Pt-based catalysts with specific supports in PEMFCs and DMFCs are also discussed The nanosystems of as-prepared Pt nanoparticles as well as Pt-based nanoparticles with various mixture, alloy, and core-shell structures are of great importance to nextgeneration FCs Low-cost Pt-based mixture, alloy, and core-shell nanoparticles have been shown to have the advantages of excellently durability, reliability, and stability for realizing FCs and their large-scale commercialization The latest trend in the use of new non-Pt alloys or new alloys without Pt but they have high catalytic activity as the same as to that of Pt catalyst has been discussed We propose a new method of atomic deformation, and surface deformation as well as nanoparticle and structure deformation together with plastic and elastic deformation at the micro- and nano-scale ranges by heat treatments at high temperature can be applied for enhancement of catalytic activity, stability and durability of Pt catalyst and new non-Pt alloy and oxide catalysts in future while the characteristics of size and shape can be retained Finally, there has been a great deal of demand to produce catalytic nanosystems of homogeneous Pt-based nanoparticles because of their ultra-high stability, long-term durability, and high reliability as well as the durable and stable nanostructures of Pt-based catalysts with carbon, oxide and ceramic supports Such materials can be utilized in FCs, and they pose new challenges to scientists and researchers in the fields of energy materials and FCs In addition, the importance of Pt based nanoparticle heat treatment with, and without the nanoparticle surface deformation or nuclei surface deformation is very crucial to discover a new robust Pt based catalyst for alcohol FCs The new urgently trend of producing various novel alloy catalysts replacing Pt catalyst but similar catalytic activity is confirmed in the avoidance of the dependence of Pt-noble-metal catalyst in both the cathode and the anode of FCs & 2013 Elsevier Ltd All rights reserved Contents Introduction 637 Low-temperature fuel cells 638 Fuel cells 638 Proton-exchange membrane fuel cell (PEMFC) 638 Direct methanol fuel cells (DMFC) 639 Platinum catalyst 640 Characterization of Pt- and Pd-based nanoparticles 643 Development of Pt-based catalysts 644 Development of Pt-Ru-based catalysts (PtxRuy and PtxRuy/support) 646 Development of Pt-Rh-based catalysts (PtxRhy and PtxRhy/support) 647 Development of Pt-Au-based catalysts (PtxAuy and PtxAuy/support) 647 Development of Pt-Cu-based catalysts (PtxCuy and PtxCuy/support) 647 Development of Pt-Ni-based catalysts (PtxNiy and PtxNiy/support) 648 Development of Pt-Co-based catalysts (PtxCoy and PtxCoy/support) 648 Development of Pt-Sn-based catalysts (PtxSny and PtxSny/support) 648 Development of Pt-Fe-based catalysts (PtxFey and PtxFey/support) 648 Development of Pt-and-Pd-based nanoparticles (PtxPdy and PtxPdy/support) 649 Development of Pt- and Pd-based catalysts with carbon and oxide supports 661 Development of novel alloy-based catalysts (alloy and alloy/support) without Pt 663 Stability and durability 663 Conclusion 664 Acknowledgments 664 References 665 Introduction Several known direct chemcal-electrical energy conversion processes in various fuel cells (FCs) with high efficiency and low pollutant emission have been studied [1,2] Recently, the U S Department of Energy Fuel Cell Technologies Program (DOE Program) and the New Energy and Industrial Technology Development Organization (NEDO Program) in Japan have financially supported large research and development programs (R&D) concerning FCs and FC systems for stationary, 638 portable, and transportation applications, such as FCs for cars and vehicles as well as for portable devices, such as laptop computers and mobile devices [3–7] In PEMFCs and DMFCs, Pt catalysts are mainly used to provide catalytic activity, typically for reactions such as oxygen reduction reactions (ORRs) or hydrogen evolution reactions (HERs)/hydrogen oxidation reactions (HORs) In addition, very important ORRs have also been examined in studies of Pt-based catalysts with transition metals, typically Pt, Ir, Os, Pd, Rh, and Ru, for their applications for the enhancement of current density in FCs [8–10] Ru, Os, Rh, Ir, Pd, Pt, Ag, and Au are precious metals of great importance in catalysis [11] A Pt-based catalyst in the catalyst layer is one of the main elements of powergeneration membrane-electrode-assembly (MEA) technology in PEMFCs and DMFCs [7], which utilizes various protonconducting membranes, such as Nafion-type membranes [7,18] The roles of the dissolved gases (O2, H2, and N2) in the solvent medium have been proven via their interactions and reactions to certain shapes and morphologies of Pt and Pd nanoparticles [12] The specific catalytic properties of metal nanoparticles on various supports with respect to the effects of size, shape, morphology, porosity, surface, structure, support, composition, and oxidation state have been discussed previously [13] Besides, it has been established that the ability to control particle sizes is very crucial to create good and robust Pd-based catalysts in place of Pt [14] At present, various proton-exchange membranes with high quality and long-term stability are used for FC applications below or above 100 1C [15] The best efforts toward improving the electrocatalytic activity of pure Pt catalysts have been conducted in the process of testing Pt-based catalysts in DMFCs and PEMFCs [16] In addition, a large number of the various support materials for PEMFC and DMFC electrocatalysts have been reviewed [17,18] Analogously, other noble-metal electrocatalysts can be used in a promising structural paradigm for DMFCs [19] The catalyst layer is of great importance to efforts to decrease the very high cost of FC products, as it constitutes more than 50% of the cost For this reason, Pt and Pt-based alloys have been developed for next-generation PEMFCs and DMFCs [6,20] Pt-based nanowires can be used as potential electrocatalysts in PEMFCs [21] The improved manufacture of Pt nanoparticles with a well-defined size, composition, and shape via chemistry can lead to a very good catalyst with high selectivity and thermal stability, especially in future FCs [22,23] The challenges of designing Pt-based electrocatalysts have been considered in the context of automotive FC applications [24] Moreover, various novel Pt-based catalysts have been proposed for PEMFCs [25] Proposals and ideas for novel low-Pt-loading catalysts in PEMFC or DMFC systems have been presented, and the catalytic activity and stability of ORR catalysts that use metal and bimetal nanoparticles in various FCs have been compared [26,27] The avenues for improving Pt- or Pd-based catalysts involve shape- or size-dependent catalytic activity, instability and surface-area loss, dealloying phenomena, and the synergistic effects of bimetallic catalysts Incredible differences between the catalytic activity of a homogeneous catalytic system of synthesized Pt nanoparticles and that of an inhomogeneous catalytic system of synthesized Pt nanoparticles have been observed in the relations between their preparation processes, structures and properties The rapid development of direct alcohol FCs N.V Long et al (DAFCs) has primarily involved the design and discoveries of new materials and catalysts [28] The HOR and MOR mechanisms have been intensively studied with the goals of improving the long-term durability, stability and cost of PEMFCs and DMFCs In particular, the price of FCs mainly depends on the price of the Pt-based catalysts or on the design of catalysts that use a low Pt weight or no Pt at all In this review, we present the latest developments in asprepared Pt-based nanoparticles for use as the Pt-based catalysts for alcohol FCs, particularly PEMFCs and DMFCs The issues of nanosized ranges of Pt-based nanoparticles are discussed with respect to the related degrees of stability and durability in alcohol FCs The advantages of polyhedrallike and spherical-like shapes and morphologies are also discussed for the purpose of identifying the best Pt-based catalysts for various applications of growing concern It is certain that the issues of tuning, controlling, and shaping Pt-based nanostructures within certain size and shape ranges are usually much more difficult than controlling the metal compositions of Pt-based nanostructures To achieve large-scale commercialization of FCs, various designed Pt nanoparticles in the mixture, alloy and core-shell categories have been tested to determine whether they meet the demands of high catalytic activity Importantly, in this review, we propose new catalytic models for the use of pure Pt-based nanoparticles on and inside of supports, leading to improvement in the catalytic activity and sensitivity of Pt-based nanoparticles that are loaded on various supports, such as carbon, oxide, and ceramic, to maximize their durability and stability The excellent recently achieved advantages of Pt-based catalysts with mixture, alloy and core-shell nanostructures have been confirmed in testing and measurements Low-temperature fuel cells Fuel cells Proton-exchange membrane fuel cell (PEMFC) In principle, a PEMFC with a polymer membrane electrolyte and a pure Pt catalyst has a low operation temperature of o90 1C The electrochemical reactions that occur in a lowtemperature PEMFC are as follows [29,52] Cathode: 1/2 O2+2H++2e H2O (ORR); Anode: H2-2H++2e- (HOR) (1) Overall reaction: 1/2 O2+H2-H2O (Fuel cell reaction) (2) At present, Pt-metal catalysts are the most active toward the hydrogen oxidation reaction (HOR) that occurs at the anode in PEMFCs To achieve a low-cost FC design, the very high Pt catalyst loading must be decreased Two strategies are under investigation for reducing the Pt loading in PEMFCs: the fabrication of binary and ternary Pt-based alloyed nanomaterials and the dispersion of Pt-based nanomaterials onto high-surface-area substrates, such as carbon nanomaterials To reduce the cost associated with pure Pt catalysts, Pt-based catalysts have been widely developed At present, carbon monoxide (CO) poisoning still occurs at the anode, and CO can heavily adsorb on a Pt-based catalyst and block the hydrogen The Development of Mixture, Alloy, and Core-Shell Nanocatalysts with Nanomaterial Supports for Energy Conversion oxidation To improve the stability and activity of the HOR on a pure Pt catalyst, different base metals can be added to reduce CO poisoning Because of such efforts, Pt- and Pdbased catalysts with various mixture, alloy, and core-shell nanostructures have been developed In addition, novel COtolerant catalysts will necessarily be developed in large amounts but at low cost Thus far, the Pt-based bimetallic nanoparticles for Pt-based bimetallic catalysts that have been studied are Pt-Ru, Pt-Fe, Pt-Cu, Pt-Mo, Pt-Ni, Pt-Sn, Pt-Re, Pt-W, Pt-Ir, Pt-Os, Pt-Rh, Pt-Pd, Pt-Au, and Pt-Ag in mixture, alloy and core-shell structures [55,376,377] In addition to various alloy and core-shell nanostructures, a wide variety of material mixtures can be used for the development of PEMFCs As a result, the catalytic activity and stability of Pt-based alloy and core-shell catalysts are greatly enhanced with respect to those of pure Pt catalysts In recent research, various binary, ternary and quaternary Pt-based catalysts using metals such as Pt, Ru, Rh, Pd, Ir, Os, Au, Ag, Cu, Ni, Fe, Co, Mn, Zn, Mo, Sn, and W have been prepared for the purpose of obtaining catalysts with higher catalytic activity and stability [2,56,57] A shape transformation from Pt nanocubes to tetrahexahedra with a size of near 10 nm, leading to an influence on the catalytic activity of a Pt nanoparticle catalyst, was observed in one study [58] In general, such tetrahexahedral Pt nanoparticles in this size range had a high density of step atoms They exhibited an enhancement of electrocatalytic activity toward ethanol oxidation [58] However, the complexity of the preparation processes was high These catalysts can be used on various carbon nanomaterials, such as CNT and Vulcan-XC-72R, to provide a significant enhancement of catalytic activity Modified catalysts that not contain Pt are being considered to avoid the dependence on Pt metal The use of various PtRu-alloy/C catalysts in the anodes of DMFCs has been reviewed previously [56] These catalysts can also be used as CO-tolerant catalysts in the anodes of PEMFCs In addition, Pt-alloy catalysts have exhibited improved catalyst behavior for novel cathodes of both PEFCs and DMFCs [56] Because of their high stability and durability, Pt-alloy catalysts can be used for the large-scale commercialization of automotive FCs [57] The potential PEMFC applications of Pt- and Pt-Ru-based catalysts of mixed metal nanoparticles have been discussed previously [2,56], especially those of Pt/C and Pt-Ru/C catalysts that use ordered mesoporous carbon [2,56,57] Direct methanol fuel cells (DMFC) Instead of hydrogen fuel, methanol is used in DMFCs It is known that DMFCs have a low operation temperature of 40– 100 1C when they are constructed using MEA technology with a proton-exchange membrane, such as Nafion, as the electrolyte, and there is a direct MOR at the anode of DMFCs Methanol offers advantages over hydrogen as a fuel, including ease of transportation and storage and a high theoretical energy density Pt is the most promising candidate among the pure basic metals for application in DMFCs because Pt exhibits the highest activity to the dissociative adsorption of methanol However, a pure Pt catalyst is easily poisoned by CO, which is produced as a by-product of the MOR at room temperature Pt-based catalysts can be used in the electrodes, both the anode and the cathode In 639 principle, the operation of a DMFC primarily depends on the chemical reactions at the electrodes, as follows Cathode: 3/2O2+6H++6e 3H2O (ORR); Anode: CH3OH+H2O-CO2+6H++6e- (MOR) (3) Overall reaction: CH3OH+3/2O2-CO2 +2H2O (Fuel cell reaction) (4) Currently, hydrogen/oxygen PEMFCs and DMFCs mostly employ Pt-based catalysts for portable power generation, especially in compact mobile devices At present, alcohol technology has been well developed for high-purity Pt catalysts Therefore, the surface kinetics of the Pt catalyst and its catalytic activity with respect to hydrogen and alcohol fuels have been extensively investigated and demonstrated [1–10] To improve the performance of DMFCs and reduce their costs, Pt-based catalysts must yet be considerably further developed Thus far, Pt-Ru-based catalysts have been very successfully used for the cathode reaction in DMFCs, but only at high cost [59–62] The CO poisoning that is strongly adsorbed on Pt atoms on the surfaces of Pt-Ru is addressed by reduction by the Ru metal atoms, leading to the poisoned Pt surface becoming very active to the MOR with the following bi-functional mechanism [18,59,61] Ru+H2O-Ru-OH+H++eÀ (5) Ru-OH+Pt-CO-Pt+Ru+CO2+H++e(General mechanism) (6) The above two equations are the most general mechanisms of CO-poisoning reduction in most Pt-based alloy catalysts that use low concentrations of Ru or other various base metals Therefore, exploiting the bi-functional mechanism (or various possible multi-functional mechanisms for Pt-based multi-metal catalysts) for the reduction of CO poisoning is a good way to improve FC systems, such as PEMFCs and DMFCs, as a whole Similarly, Pt-based bimetallic catalysts have been developed for DMFCs These can be many types of Pt-M-based catalysts, where M may be Co, Ni, Fe, Cu, Cr, or other cheap and abundant metals Thus, there are many available Pt-based mixture catalysts, including various binary, ternary and quaternary Pt-based catalysts Accordingly, a Pt-Ru-Rh-Ni-based catalyst has been prepared for the sake of achieving a high MOR rate in DMFCs, although it suffers from the high complexity of its composition Similar trends have led to a reduction in the amount of Pt metal used [63] and the development of new Pt-based catalysts with carbon nanomaterials, such as Pt/C, PtSn/C, PtRu/C, and Pt/CeO2/C [381] as well as Pt/FeRu/C, Pt/ NiRu/C, and Pt/CoRu/C [382], with the goal of reducing the total cost of DMFCs We must develop Pt-based catalysts, or good catalysts without Pt, that not only resist CO poisoning but also prevent it and maintain CO poisoning in the MOR at a suitable minimal level, or we must develop CO-tolerant Ptbased catalysts In CO poisoning, intermediates that are generated by oxygen reduction, such as hydroxyl and oxide groups, can firmly adsorb on the surfaces of the nanocatalysts, which will decrease the overall performance of the catalytic activity The issue of CO poisoning can be understood by the mechanisms of Pt-COad and a second metal atom, a third metal atom, and so forth reacting with their OH groups, e.g., M-OH reacts to form CO2 This 640 characterization is a so-called bi-functional mechanism (Ptbased bimetallic nanoparticles with alloy and mixture structures) or a complex multi-functional mechanism (Pt-based multi-metal nanoparticles) Accordingly, a simple solution is to find a suitable metal that acts against CO poisoning and can be used in Pt-based-alloy catalysts The known Pt/C, Ptoxides/C, Pt-Ru/C, and Pt-Ru-oxides catalysts are promising candidates for novel DMFC electrodes The various carbon nanomaterials used are carbon (C) black, C-nanotubes (CNTs), C-nanofibers (CNFs), C-nanowires (CNWs), etc., and the other various supports are oxides, glasses, ceramics, composites, or mixtures, typically WO3, SnO2, SiO2, etc [64] The primary issue facing Pt/C-based catalysts is the corrosion of the carbon by water over time [65] Therefore, the investigation of the catalytic behavior of metal-, bimetal-, and multi-metal-based nanoparticles on carbon supports as well as novel supports such as glass and ceramics is important for future developments in nanocatalysis, energy conversion, PEMFCs and DMFCs At present, single metal nanoparticles, such as Cu, Ag, Au, Pt, Pd, Ru, Rh, Ir, Os, Ni, Fe, and Co, and the chemical and physical methods by which they can be synthesized are of importance to various FC sciences and technologies [66–69] FC materials with non-homogeneous sizes and heteromorphology from several nm to μm can be synthesized with the ultrasound method However, the challenge is to obtain a homogeneous size and morphology [70] At present, pure ultrafine Pt clusters of approximately 0.88 nm on commercial carbon can be used for the DMFC reactions [71] However, a quick collapse in the nanostructure of Pt nanoparticles and a corresponding decline in catalytic activity have been discovered in the particle-size limit of o1 nm [72] This phenomenon affects the catalytic sensitivity and activity of Pt-based nanostructures Most ultrafine or very small metal nanoclusters exhibit very high catalytic activity but no confirmed stability or durability; for example, very tiny Au and Pt clusters can be used to achieve much higher ORR rates, but their stability and durability cannot be reliably confirmed [73] In addition, Pt nanoparticles of approximately 2–5 nm in size on carbon supports are known to be the best catalysts for ORRs, and very small Pt clusters exhibit very high catalytic activity for the fourelectron reduction of oxygen molecules [74] At present, metal and bimetal nanoparticles of different shapes have high potential for applications in catalysis and energy [75,76] Among the noble nanoparticles, platinum (Pt) and palladium (Pd) are of importance for their utilization in the catalyst layers of PEMFCs and DMFCs in both the cathode and the anode In general, most noble-metal nanoparticles can be shaped in size and morphology below or above 1000 nm; sizes of less than 10 or 20 nm are of particular interest for their excellent potential for application in catalysis, biology and medicine because of their large quantum-size and surface effects Small, strong adsorbates or adsorbents (e.g., IÀ, CO, amines) are crucial for providing size and shape control during the synthesis of Pd and Pt nanoparticles [77–80] A Pt/C catalyst that uses functionalized ordered mesoporous carbon has been utilized for DMFCs [81] In addition, a graphene-nanoplate-Pt catalyst has been demonstrated to serve as a high-performance catalyst for DMFCs [82] At the same time, various types of new membranes have been developed for DMFCs with the N.V Long et al use of the above modified catalyst layers [83] In many cases, Pd nanoparticles can be replaced with Pt nanoparticles, despite alcohol the lower catalytic activity of the latter The effect of pseudo-halide thiocyanate ions on the seed-mediated growth of Pd nanocrystals has been investigated [84,85] In the synthesis of metal nanoparticles via chemistry and physics, most of the metal nanoparticles are shaped to size and morphology ranges of less than 10 nm, approximately 100 nm, and 1000 nm or more [86] In general, nanoparticles of a homogeneous size and morphology offer excellent properties in practical applications We suggest that the ability to shape metal nanoparticles or bimetallic nanoparticles of both noble and cheap metals to size and morphology ranges of approximately 10 nm, approximately 20 nm, and approximately 30 nm is extremely important to catalysis and FCs The size and morphology of Pt nanoparticles or Pt-based nanoparticles can be maintained by storing these nanosystems in various suitable solvents The issues of the dissolution of noble metals (Pt, Au, Pd, Rh, and Ru) from the nanoparticles or the catalysts in electro-chemical measurements and the experimental conditions of DMFCs or PEMFCs must be further investigated To improve the catalytic activity and durability of pure Pt catalysts, the specific effects of synergistic, dealloying, Janus, and composition effects have been given particular consideration in Pt- and Pd-based mixture, alloy and core-shell nanoparticles The most popular nanosystems of Pt-based catalysts for alcohol FCs, PEMFCs and DMFCs are those that utilize bimetallic nanoparticles They include PtxAuy, PtxRhy, PtxPdy, PtxCuy, PtxNiy, PtxFey, and PtxSny as well as polymetal nanoparticles, such as PtRuRh The reduction of the very high cost of pure Pt catalysts the focus of much current research At the same time, it may also be possible to enhance the catalytic activity for the HOR, reduce CO poisoning (by using the various base metals discussed above), and increase the ORR rate (for the sake of a large current density), all of which contribute to the high stability and durability of FCs The composition of Pt-noblemetal- and cheap-metal-based catalysts can be adjusted to obtain various desirable Pt-based catalysts of high catalytic activity, high durability and high sensitivity by reducing the level of CO poisoning Platinum catalyst To date, pure Pt catalysts have been the most commonly used catalysts for FCs Novel FC catalysts (Pt-based catalysts and carbon or oxide supports) have been under continuous development, but they have not completely replaced Pt catalysts In recent years, Pt nanoparticle catalysts have played a key role in the sustainable hydrogen economy because Pt is the best catalyst for the hydrogen oxidation and oxygen reduction reactions at the anodes and cathodes of FCs [23,29] At present, many metal nanoparticles, such as Au, Ag, Pt, Pd, Cu, Rh, Rh, Ru, Ni, Co, Fe, and Mo nanoparticles, are used in electrocatalysis The controlled synthesis of noble- and cheap-metal nanoparticles in particular size ranges of 10 nm (1–10 nm), 20 nm (1–20 nm), 30 nm (1–30 nm), etc with well-controlled shapes and morphologies, such as the polyhedral and polyhedral-like categories (tetrahedra, octahedra, cubes, etc.) and the The Development of Mixture, Alloy, and Core-Shell Nanocatalysts with Nanomaterial Supports for Energy Conversion spherical and spherical-like categories, is critical for FC electrocatalysts in DMFCs and PEMFCs, especially the synthesis of Pt nanoparticles in the range of 10 nm [1,2,29–31] However, among the above-listed elements, Pt noble metal is known to be the best metal electrocatalyst for the FC reactions, which include the hydrogen evolution reaction (HER)/hydrogen oxidation reaction (HOR), the oxygen oxidation reaction (ORR), and the electrooxidation of carbon monoxide (CO) The issue of CO poisoning in the HOR on pure Pt catalysts is well known The effect of such CO poisoning of Pt-based catalysts at the anode should be significantly reduced to achieve the best FC performance To minimize CO poisoning, Pt-based catalysts can be heated at high temperatures in N2/H2 [134,135] As another method of dealing with this problem, Pt-based bimetallic and multi-metal nanoparticles have been developed for use in the catalyst layer [389] In this way, the CO poisoning will be controlled by reduction by a second metal, a third metal, or even more This is an excellent method of avoiding and preventing anode failure In addition, highly CO-poisoning-resistant catalysts must be developed for the anode or fuel electrode The surfaces of the Pt nanoparticles are very important to nanocatalysis Polyhedral Pt nanoparticles typically exhibit mainly low-index facets of (100), (110), and (111), although they include high-index facets, (h k l) Nevertheless, in the typical TEM method, a certain number of the (h k l) planes of the low- and highindex planes was determined in the selection rule for the various types of fcc crystal structures because of the limitations of the TEM method In addition, certain peaks have been characterized as (111), (200), (220), (311), and (222) peaks by the XRD method [32] The dependence of the catalytic activity on the surfaces of the prepared Pt nanoparticles has been determined for various categories of the Pt nanostructures [33–35] Furthermore, catalytically active Pt atoms belonging to the low-index facets of (111), (100) and (110) of the Pt nanoparticles have been shown to have high stability and durability in nanocatalysis, as indicated by electrochemical measurements, and good reconstruction in the highest catalytic reactions in various FCs [36–38] Pt nanoparticles that have been engineered via facile and successful preparation methods based on chemistry and physics can be used for FC applications, such as PEMFCs and DMFCs [66–70,155] In typical electrochemical measurements of pure Pt catalysts, the electrode is usually swept from E = - 0.2 to E= 1.0 V with respect to the saturated hydrogen electrode (SHE) In such measurements, specific regions are observed in the cyclic voltammogram that exhibit catalytic activity and surface kinetics for the case of pure Pt catalysts Regarding hydrogen catalytic activity, the HER on the Pt catalyst is described by the important Volmer, Tafel, and Heyrovsky mechanisms In addition, the Volmer-Tafel and Volmer-Heyrovsky mechanisms also occur in the complex combinations of the basic mechanisms As a rule, the surface kinetics and chemical activity that occur at the surface of electrodes that contain pure Pt catalysts as well as those that contain mixtures of Pt/supports are characterized by the catalytic activity of Pt with respect to hydrogen and oxygen atoms and to water [1–10,39–41] In the mechanisms of the catalytic activity, selectivity and sensitivity of pure Pt nanoparticles with respect to 641 Figure Trends in oxygen reduction activity as a function of the oxygen binding energy The highest ORR of Pt and Pd base metals are theoretically calculated in the proof as important factor to enhance the current density in fuel cells, PEMFC and DMFC Reprinted with permission from: J.K Nørskov, J Rossmeisl, A Logadottir, L Lindqvist, J.R Kitchin, T Bligaard, H Jónsson, J Phys Chem B 108 (2004) 17886-17892 [42] Copyright © 2004 American Chemical Society hydrogen, there are surface chemical and physical differences that arise as the pure Pt-metal catalyst changes into PtO oxide, but these differences may exist only on the surfaces The important effects of the thickness of the PtO oxide, which are relevant to the inverse change of the PtO oxide into pure Pt-metal catalyst during the general processes at the electrodes, have not yet been thoroughly examined Therefore, further study of the formation of Pt-H and Pt-O through the catalytic activity of Pt with H and O is very crucial and may lead to the enhancement of the catalytic activity of Pt-based catalysts, which, in turn, will improve low-temperature FCs, PEMFCs and DMFCs In acidic electrolytes, the ORR is observed to follow two main pathways, one with four electrons transferred directly and one with two electrons transferred consecutively [39–41] To evaluate the catalytic activity of the prepared nanocatalysts, the electrochemical active surface area (ECA) of the various pure Pt-based catalysts has been calculated to be QH0.21 Â LPt [39] Here, the specific charge transfer (QH) due to hydrogen adsorption and desorption is calculated as QH = (QTÀQDL)/2, where QT denotes the total amount of charge during hydrogen adsorption and desorption on Pt sites, and QDL is related to the charge due to the doublelayer capacitance The area within the curve in the relevant region can provide QT and QDL and can be obtained by taking the area under the same region, but with upper and lower boundaries of horizontal lines passing through a data point outset of the hydrogen desorption/adsorption waves A conversion factor of approximately 0.21 (in mC cmÀ2) can be used for a monolayer of hydrogen In this context, the value of LPt corresponds to the loading of the Pt catalyst on the glassy carbon surface (in mg cmÀ2) [39–41] As discussed previously, the catalytic characterization of Pt nanoparticles has involved investigation into the size, shape, morphology, and structure of Pt nanostructures as well as various effects of composition modifications To obtain a performance enhancement with respect to pure Pt 642 catalysts, Pt-based catalysts of various categories, such as mixture, alloy, and core-shell structures, have been developed In the operation of FCs, the most important concerns are that the ECA and the QH should be high and that the loading LPt should be low At present, the phenomena of the ORR kinetics and mechanisms that occur on Pt catalysts have been intensively investigated, but a very high overpotential loss has been observed, indicating that hydrogen peroxide (H2O2) is formed before the formation of water molecules Therefore, very high loadings of Pt must be used for the operation of FCs with large currents It is known that the Pt catalyst has exhibited the highest activity with respect to the ORR mechanism In recent years, much research has been conducted with the goal of understanding the ORR in catalytic systems with Pt catalysts that are designed to use the minimal level of ultralow Pt loading However, the challenges of low Pt-catalyst loading, high performance, durability, and cost-effective design in FC systems remain very crucial for the large-scale commercialization of such systems The cyclic voltammetry (CV) results of various Pt nanoparticles (spherical, cubic, hexagonal and tetrahedral-octahedral morphologies) in HClO4 or H2SO4 have illustrated the strong structural sensitivity of as-prepared Pt nanoparticles The most basic and stable (111), (100) and (110) planes with high densities of highly active Pt atoms have been confirmed in the active sites of specific catalytic activity, such as in the edges, corners, and terraces [36,111,112] Further investigations of the HER, HOR, and ORR mechanisms in asprepared catalyst layers are crucial to obtaining high currents Nanostructured catalysts must have high hydrogen solubility and reactivity In addition, fast, sensitive, and stable hydrogen desorption/adsorption could be very crucial for FCs Currently, catalysts that are designed for FCs must have a high and stable ORR rate To obtain large current densities in PEMFCs and DMFCs, we must study the ORR mechanism in detail and develop novel Pt-based catalysts Interesting studies have performed densityfunctional-theory (DFT) calculations of the energies of the surface intermediates for a number of metals, both expensive, rare, noble metals such as Pt, Pd, Au, and Ag and abundant, cheap metals such as Cu, Ni, Fe, and Co, as shown in Figure [42,43] As a result, a clear volcanoshaped relationship was established between the rate of the cathode reaction and the oxygen-adsorption (Oad) energy From this useful model, which involves the dband center or d-state of various base metals, Pt and Pd were determined to be the two elements that are the best choices for cathode materials (Figure 1) It is likely that a Pd-based catalyst can replace a Pt-based catalyst in the cathode for the ORR in PEMFCs and DMFCs, reducing the dependence on Pt, which is an expensive and rare precious metal [42–44] To enhance the catalytic activity, stability and durability of the catalysts, various Pt/support catalysts have been studied as part of the continuous development of low-temperature FCs, such as PEMFCs and DMFCs Pt, Pd, and Pt- and Pd-based bimetallic nanoparticles with sizes of 10 nm and 20 nm on carbonnanomaterial supports have been evaluated for potential applications involving the direct methanol oxidation reaction (MOR) It has been found that pure Pt nanoparticles must be highly dispersed on the supports to obtain the best N.V Long et al catalytic activity for the operation of FCs In catalyst engineering, the microwave-assisted polyol method has been used for the preparation of Pt/C, Ru/C and PtRu/C catalysts for the MOR [45] PtRu/C electrocatalysts and PtRu-graphitic mesoporous carbons (GMCs) have been synthesized for evaluation for MOR applications The results indicate that the role of the various pore sizes of the GMCs is especially important in determining the performance of DMFCs [46] In one study, it was found that the electrodeposition of Au, Pt, and Pd metal nanoparticles on carbon nanotubes (CNTs), such as singlewalled CNTs (SW-CNTs), could be performed via a twoelectrode arrangement An issue of concern for Pt/C catalysts is the corrosion of the carbon by water, which can cause a significant decrease in the catalytic activity in both PEMFCs and DMFCs In the future, we expect that novel supports (metals, alloys, oxides, and ceramics) with the same catalytic activity as carbon will be developed that can replace the carbon supports However, carbon supports are of importance to low-temperature FC catalysts [47] Accordingly, a microwave-heated polyol synthesis of a Pt/CNTs catalyst for methanol electro-oxidation has been presented [48] Pt is expensive, and Pd can be used to replace Pt in many cases [49–51] Some authors have proven that by adding a very small amount of Pt (5 at %) to a Pd-based catalyst, the HOR activity of the Pd-based catalyst can increase to nearly the same as that of a pure Pt catalyst These results can serve as a foundation for the suitable utilization of noble Pt metal in FCs [52,378], for example, Pd-based electrocatalysts with a thin layer of Pt (5 wt%) [378] The catalytic properties of as-prepared Pt nanoparticles are strongly affected by the nature of their surface structure and internal structure, including factors such as roughness, sharpness, flatness, smoothness, porosity, the atomic density of the particle surface, chemical bonding, and chemical and structural changes [53] In the recent research, Pt-based metallic and bimetallic nanoparticles with alloy, core-shell, and mixture nanostructures have been synthesized and developed for the purposes of catalysis, energy conversion, environmental friendliness, and FCs In Figure 2, pure as-prepared Pt nanoparticles that were prepared with shape-controlled synthesis are shown to be in the size range of 10 nm with a highly homogeneous distribution in size and morphology, which is required for a good characterization of a catalytic system In most cases, the chemical reactivity can be increased through nanostructuring because of the resultant increase in the ratio of reactive surface atoms to non-participating bulk atoms In a particle with a diameter of 20 nm, only approximately 10% of the atoms are on the surface, while in a particle with a diameter of nm, the proportion of reactive surface atoms is approximately 99% [54] In nature, a given number of larger Pt particles has a much higher durability and stability than the (larger) number of small Pt nanoparticles with the same total weight of Pt metal, but their catalytic activity is much smaller than that of the small Pt particles In other words, a nanoparticle with a very small particle size, in the range of 10 nm, has a larger relative number of surface atoms and therefore a higher catalytic activity compared to a larger particle, but it is clear that very small particles have less structural durability and stability Because of the high The Development of Mixture, Alloy, and Core-Shell Nanocatalysts with Nanomaterial Supports for Energy Conversion 643 Figure (a)-(f) TEM images of the uniform Pt nanoparticles by a modified polyol method The homogeneous polyhedral Pt nanoparticles of main tetrahedral, cubic, and octahedral morphologies and truncated shapes and morphologies were clearly observed in the size range of 10 nm This proves that highest quantum-size effect in catalytic activity, sensitivity, and selectivity are achieved in the size range of 10 nm The surface attachments among the Pt nanoparticles were observed Scale bars: (a)-(c) 100 nm; (d) 50 nm; (e) and (f) 20 nm Reprinted with permission from: N.V Long, C.M Thi, M Nogami, M Ohtaki, Novel issues of morphology, size, and structure of Pt nanoparticles in chemical engineering: surface attachment, aggregation or agglomeration, assembly, and structural changes, New J Chem 36 (2012) 1320-1334 [53] Copyright © 2012 Royal Society of Chemistry (RSC), Thomas Graham House quantum-size effect, the optimization of these factors is extremely important to improve the catalytic activity and the cost of the Pt-metal loading of catalysts Characterization of Pt- and Pd-based nanoparticles At present, Pt- and Pd-based nanosystems that can be prepared with simple chemical methods with homogeneous morphology, shape, size, and structure in the nanosized range of 10 nm are extremely important to catalysis and nextgeneration FCs [87–89] The shape-controlled synthesis of single metal nanoparticles, with an emphasis on various Pt nanostructures, is discussed, along with its crucial role in the electrocatalysis of anodic reactions in PEMFCs A clear shape and size –dependence of catalytic activity has been demonstrated [33] Various methanol-tolerant Pd nanocubes have been compared in terms of their catalytic activity for ORR in H2SO4 electrolyte, showing that the catalytic activity of all types of Pd nanocubes is better than that of normal Pd nanoparticles [88] The MOR can be used as a probe reaction on Pt dendrites and cubes to determine their effect on the MOR as a function of particle shape and morphology [90] Pt/C catalysts have been very successfully used for PEMFCs [91] A more active Pt/C catalyst for DMFCs has been developed [92] However, for the 10-nm size range, hetero-characterizations of shape, morphology, size, structure, and surface are also very crucial to understanding the natures of nanoclusters, nanocrystals and homogeneous and non-homogeneous nanosystems for FCs The ability to control the size and shape of Pt or Pd nanoparticles is very crucial to catalysis and FCs, especially DMFCs and PEMFCs [93–96] A nanoporous Pd rod catalyst was developed for MOR [97] In general, ethylene glycol (EG) (and other various alcohols) has been shown to be one of the most important organic compounds used as a chemical intermediate in a large number of industrial processes EG can be used as the reducing agent or the solvent for the successful syntheses of various metal, bimetal, or multimetal nanoparticles [98] The kinetics of the ORR on a Pd catalyst in acid media is very crucial to enhance the performance of PEMFCs [99] The effect of the nature of the precursor has been investigated with regard to the performance of Pd-Co catalysts for DMFCs [100] A strategy for controlling bimetallic nanostructures, e.g., Pd-Au, by seedmediated co-reduction has been proposed [101] Structuresensitive catalysis in Pt catalysts has been confirmed in the (111), (100), and (110) low-index facets [102,103] The shapedependent catalytic properties of Pt nanoparticles depend on their specific crystal nanostructures [104] However, the highindex facets of metal nanoparticles, such as the (557) and (730) surfaces of Pt nanoparticles, also play a crucial role in morphology-dependent catalysts [105] Tetrahexahedral Pt nanoparticles of high catalytic activity with average sizes of 644 53, 100, 126, and 144 nm exhibit 24 high-index facets, such as the {730}, {210}, and/or {520} surfaces, with a large density of atomic steps and dangling bonds [106] Because of the higher concentration of surface steps, kinks, islands, terraces, and corners in their surfaces and morphologies, superior catalytic performance has been obtained for un-sharp Pt nanoparticles [107,108] The instability and surface-area loss of Pt/C electrocatalysts at high voltages in low-temperature FCs have been shown [109] Pt and Pt-based catalysts have both been considered for use in low-temperature FCs Meso/nanoporous metal structures possess much higher surface areas and higher catalytic activities than non-porous catalysts, but their stability and durability have yet to be proven [110] Highly active selective Pt-based catalysts have been proposed, with an emphasis on the various roles of the kinks and steps [35] and the active sites on Pt nanoparticles [108,109] It is remarkable that the complexity of the surface, surface structure and morphology of Pt nanoparticles has been clearly confirmed In addition, various possible visible (h k l) indices have been assigned to fcc structures of specific (h k l) low and high indices, including (111), (200), (220), (311), (222), (400), (311), (420), (422), (333), (511), (440), (531), (442), (600), (620) and (533) [32] The synthesis methods for nanoparticles of Pd and its alloys have been discussed in the context of FC applications [52,113] The general methods for the shape-controlled synthesis of Pd nanocrystals in aqueous solutions with size and morphology control have been presented previously [114] Clearly, Pt and Pd nanoparticles are of importance to catalysis Their size, shape and morphological transformations are crucial for the long-term stability of Pt- and Pd-based FC technologies The complex morphologies of Pt and Pd nanoparticle catalysts over the entire nanoscale have been studied from both theoretical and experimental perspectives The relative stability of nanoparticles of various shapes and sizes has been found for various Pt and Pd nanostructures [115] Hollow-structured nanoparticles with an appropriate voidto-total-volume ratio can be stable at high temperatures with respect to an increasing stable-void size with increasing temperature [116,117] Pd-based catalysts are used for alcohol oxidation in half-cells and in direct alcohol FCs [118] In the DFT method, computational results of the catalytic reactions at the surfaces are used for comparison with experiments The catalytic activity may be tuned by engineering the electronic structure of the active surface by changing its composition and structure [43,44] Bimetallic Pd-Pt nanoparticles have exhibited a significantly enhanced electrocatalytic activity with respect to pure Pt or Pd nanoparticles [119] At present, DMFCs are a key enabling technology for the direct conversion of chemical energy into electrical energy Using DFT calculations, the ORR on model electrodes has been studied The reactivity has been found for a set of monometallic and bimetallic transition-metal surfaces, both flat and stepped, that included Pt-based alloys with Ru, Sn, and Cu as well as non-precious alloys, overlayer structures, and modified edges Pt-Cu surfaces are promising anode catalysts for DMFCs [120] At present, various metals (Pt, Ru, Rh, Pd, Os, Ir, Au, Ag, Fe, Co, Ni, Cu, and Mn) are recognized as promising electrode materials for FC anodes because of the predictions of quantum mechanical calculations and DFT, especially in SOFCs [121] Because of the modifications of the surface catalytic N.V Long et al properties of noble-metal surfaces induced by the dealloying phenomenon, the electrocatalytic Pt mass activity of dealloyed Pt-Cu core-shell particles for the ORR is higher than that of a Pt electrocatalyst by more than a factor of 4, and it therefore meets the performance targets for FC cathodes [122,123] The catalytic activity and selectivity for hydrogen of various Pt(h k l) facets of Pt catalysts have been confirmed, especially the hydrogen adsorption on Pt(100), Pt(111), and Pt(110), because of the specific characterization of the corresponding Pt-metal nanoparticles [36,124– 127] Meso-structured Pt films have been prepared that exhibit high catalytic activity and stability for the ORR [128] Nanostructured tungsten-carbide/carbon composites have been synthesized with a microwave-heating method to serve as supports for platinum catalysts for methanol oxidation [129] Highly dispersed Pt nanoparticles supported on poly(ionic liquid)-derived hollow carbon spheres have been studied for the enhancement of the MOR [130] Hollow graphite carbon spheres have also been used as Pt-catalyst supports in DMFCs [131] The significant influence of the properties of CNF supports on the ORR behavior has been observed in proton-conducting-electrolyte-based DMFCs [132] At present, the design of Pt/C-based-electrocatalyst-support materials with “dense-erythrocyte-like (DEL)” and “hollow-porous-microsphere (HPM)” morphologies synthesized by spray drying is under development for highperformance PEMFC applications [133] Development of Pt-based catalysts In all research on Pt-based catalysts in FCs, the catalytic activity, reliability, durability and stability of the prepared Pt-based catalysts should be evaluated alongside their accompanying reduction of the high cost of such catalysts In one work, the authors have successfully synthesized Pt nanoparticles with various modified polyol methods with size-and morphology-control processes [53] However, the size of the Pt nanoparticles must be controlled within the size range of 10 nm or 20 nm, while the uniform shapes and morphologies must be controlled to manifest in sphericallike and polyhedral-like shapes and morphologies for better catalytic behavior In one study, pure Pt catalysts with as-prepared Pt nanoparticles of both polyhedral-like and spherical-like morphologies were investigated for their catalytic properties in methanol The results showed that the electrocatalytic performance of spherical-like and rough Pt nanoparticles is better than that of polyhedral and sharp Pt nanoparticles Pt nanoparticles have specific fringe lattices, 0.910 nm for the distance of the (100) planes, and 0.235 nm for the distance of the (111) planes Special surface-dependence catalytic properties have been confirmed for various polyhedral and polyhedral-like morphologies as well as spherical and spherical-like morphologies in the size range of 8-16 nm (20 nm) for both of the two cases above, with ECA values of $10.53 m2/g for the sharp and polyhedral-like Pt nanoparticles and 14.370 m2/g for the un-sharp and spherical-like Pt nanoparticles The catalytic activity of the as-prepared Pt nanoparticles was measured in a 0.1 M HClO4+1 M CH3OH solution A stable voltammogram was attained after 10 cycles of sweeping a potential range of -0.2 to 1.0 V for both The Development of Mixture, Alloy, and Core-Shell Nanocatalysts with Nanomaterial Supports for Energy Conversion samples The two typical oxidation peaks can be clearly observed; one is between 0.6 and 0.7 V in the forward scan, and the other is at approximately 0.50 V in the reverse scan The two peaks are directly related to the oxidation of methanol and its associated intermediate species In the reverse scan, the oxidation peak at 0.50 V can be related to the removal of the residual carbon species formed in the forward scan The peak current density in the forward scan represents the activity of a catalyst during CH3OH dehydrogenation For the prepared catalyst samples, the peak current density for the Pt nanoparticles with non-sharp and spherical shapes (14.90x10-4 A/cm2) was confirmed to be 1.51 times higher than that for the Pt nanoparticles with sharp and polyhedral shapes (9.90x10-4 A/cm2) The heat treatment of as-prepared Pt nanoparticles has been confirmed to promote advantageous electrochemical features [134] Heat treatment plays an important role in improving catalytic activity First, the as-prepared PVP-Pt nanoparticles must be washed and cleaned to remove the PVP Then, the pure Pt nanoparticles must be heated at 300 1C or higher In this way, the sizes, shapes, and morphologies of the polyhedral Pt nanoparticles can be maintained during such high heat treatment However, the removal of PVP only by heat treatment at 300 1C without washing causes a significant variation in the Pt nanoparticles, creating a sharply polyhedral shape and morphology Therefore, methods that are capable of removing the PVP without changing the characterization of the as-prepared Pt nanoparticles are stringently required to obtain good catalytic performance The self-aggregation and assembly of the as-prepared polyhedral Pt nanoparticles have been studied in the formation of large Pt particles accompanied by the decrease of catalytic activity [135,136] Therefore, the physics and chemistry methods for controlling the size and morphology of Pt nanoparticles for electrocatalysis in FCs are very important to the overall performance of the catalytic system [137– 139], for example, to ensure that the prepared Pt nanoparticles are within the desirable size range of 10 nm (110 nm), 20 nm (1-20 nm), or 30 nm Therefore, the synthesis and characterization of metallic and bimetallic nanoparticles with alloy, core-shell, and mixture nanostructures are of great importance to electrocatalysis, energy conversion, and FCs Thus far, we have successfully achieved size and shape control during the synthesis of various Pt, Rh, Pd NPs or Pt-Pd and Pt-Au bimetallic nanoparticles for catalysis and direct energy conversion by utilizing modified polyol methods Certainly, both precious and cheaper metal nanoparticles, typically Au, Ag, Fe, Co, etc., can be synthesized for catalysis, energy and FCs Therefore, metal-, bi-metal- and multi-metal-based NPs show promise for practical applications Facile methods of synthesis based on chemistry and physics can be used to prepare NPs with controlled sizes, shapes, morphologies, and structures In particular, Pt- and Pd-based nanoparticles as well as the combination of Pt and Pd NPs of certain sizes, shapes, structures, and compositions have great prospects for use in PEMFCs, DMFCs, and other energy applications Catalysts that use Pt- or Pd-based NPs can improve future FCs Therefore, continuous efforts are ongoing to engineer Pt- and Pd-based alloy and core-shell NPs in a variety of compositions using multi-metals (Co, Ni, 645 Fe, Cu …) as well as oxides, ceramics, and glasses Scientists must study the catalytic activity, selectivity, durability, and stability of these materials for application to next-generation FCs Pt clusters, nanoclusters, and nanoparticles can be synthesized with simple chemistry and physics methods, such as the modified polyol method, with or without the assistance of chemical compounds (typically sodium iodide or silver nitrate) for controlling the synthesized nanostructures Pt clusters, nanoclusters and Pt nanoparticles can be easily synthesized in the nanosize range of approximately 10 nm or 20 nm Certainly, the issues of size and morphology must be intensively studied in further catalytic investigations of Pt nanoparticles of 10 nm and 20 nm, or even 30 nm or larger, to confirm the catalytic durability, stability, and activity of Pt-NP-based catalysts In this respect, the research results on the use of a low-weight loading of Pt metal in novel robust and efficiently designed catalysts provide a good foundation for the large-scale commercialization of FCs Therefore, the controlled synthesis of Pt- and Pd-based nanoparticles is crucial to reducing the Pt and Pd loading catalysts while preserving large quantum-size or shape effects Such nanoparticles can be used as catalytic Pt and Pd shells for important bimetallic nanosystems to reduce the high costs of FC systems that use noble-metal catalysts In addition, the controlled synthesis of metal, bimetal, multi-metal, and multi-component NPs has been studied in the fields of catalysis, biology, and medicine Here, we mainly focus on the controlled synthesis of novel Pt- or Pd-based alloy or core-shell nanoparticles, or “noble-metal-based core-shell nanosystems” with noblemetal or oxide shells, and their potential applications It is certain that bimetallic or multi-metallic nanoparticles with novel homogeneous alloys and core-shell nanostructures (e.g., Pt-Fe-, Pt-Cu-, and Pt-Ni-based catalysts) can be easily synthesized However, at present, homogeneous core-shell nanosystems pose considerable challenges to researchers and scientists Accordingly, other authors have reported a study of the lattice-strain control of the catalytic activity in the dealloying of core-shell Pt-Cu catalysts that was conducted with the goal of reducing the Pt loading significantly or developing a new method of lattice-strain control [140] A synergistic effect of Pt-Pd core-shell bimetallic nanoparticles has been discovered to enhance catalytic activity and sensitivity Thus, the synergistic core-shell effects of Pt- and Pd-based bimetallic catalysts and the dealloying effects of Pt-based core-shell catalysts are very important to the creation of efficient Ptand Pd-based catalysts for developing sustainable and renewable energy sources with various FC technologies Therefore, it is still necessary to develop novel metal and/ or oxide nanoparticles, nanosized structures, and various FC materials Similarly, multi-metal NPs are promising catalysts for next-generation FCs that can be synthesized with simple chemical and physical methods Such NPs can be used in catalysis, energy conversion, and FCs, and they also have prospects for low-cost applications in the fields of thermoelectric materials, biology and medicine We suggest that the use of noble-metal thin shells (Pt, Pd, Rh, and Ru, possibly in combination with Ag and Au) and cheap-metal thin shells is of great importance to core-shell nanoparticles that are engineered for catalysis, catalysts, 662 N.V Long et al Figure The important evidences of the good integration of the pure Pt catalyst were found in TEM images of Pt nanoparticles to the supports of CeO2, ZrO2, CeO2-ZrO2 HRTEM images of Pt nanoparticles with the good characterization of morphologies and sizesloaded on the CeO2 and ZrO2 supports in In-situ analysis at 300 kV Data and results from Toyota company in testing the prepared Samples (Unpublished and limited data from Toyota Company in our testing and measurements) The possibilities of the loaded Pt catalyst on the surfaces of the supports and inside of the supports are proposed for further catalytic studies The shape, surface and nanoparticle deformations are experimentally discovered in both the size and the morphology of importance in nanoparticle science and technology Scale bars: (a)-(u) nm The Development of Mixture, Alloy, and Core-Shell Nanocatalysts with Nanomaterial Supports for Energy Conversion 663 ~4.0 nm in size have been supported on carbon with a uniform dispersion with respect to the scale of the particles and shown to exhibit good catalytic activity at high temperature [399] Recently, good Ru-decorated Pt/C catalysts have been developed for CO, methanol, and ethanol electro-oxidation [403] In general, the various carbon and oxide supports have widely been used for an significant enhancement of catalytic activity of Pt-based catalyst for PEMFC and DMFCs, such as various kinds of commercial carbon nanomaterials with good electrical and thermal conductivity In these catalysts, the activity of the Ru deposits is important for the CO oxidation and the reduction of CO poisoning To achieve the best catalytic activity for alcohol FCs, the pure Pt nanoparticles or the pure Pt-based nanoparticles must be homogeneously supported on the carbon, glass, ceramic, composite, metal and oxide nanomarterial supports, just simply by the facile mixing mothods in the alcohol solvents, such as ethanol or methanol Development of novel alloy-based catalysts (alloy and alloy/support) without Pt Recently, the scientists have discovered that MnFe2O4 alloy nanoparticles/C supports were found as efficient electrocatalysts for ORR in 0.1 M KOH solution in comparison with the traditional Pt based catalysts in their experimental [406] Fascinatingly, the new alloy catalyst/C or the Pt-like catalyst/C showed the similar behavior in ORR to the Pt/C catalysts from commercial products [403,406] This is a new alloy catalyst in place of the traditional Pt catalyst with potential use for ORR in alkaline media According to the attractive trends, we can investigate systems of the novel alloy catalysts for replacing the Pt-nobel-metal catalyst limited in natural sources In future, the above metals for their various alloy forms, are cheap and abundant, such as Mn, Fe, Ni, Co etc However, the pure Pt metal is the stardard catalyst for any comparison of catalytic activity to any novel alloy catalysts for FCs possibly discovered by chance Stability and durability At present, the effects of stress on the dissolution/precipitation of the Pt of core-shell catalysts and on cathode degradation in PEMFCs are under investigation In short, stable core-shell catalysts with Pt shells should be designed such that the shell is under tensile stress and the lattice parameter of the core is larger than that of the shell [360– 363] FC catalyst degradation has been observed on the nanoscale [364] Methanol-crossover reduction has been achieved by Nafion modification with Pd composite nanoparticles for DMFCs [365] The heat-treatment effects on the activity and stability of PEMFC catalysts for the ORR have been reviewed [366] In our personal viewpoints, we think that nanoparticle heat treatments are very important to enhance the catalytic activity of Pt-based nanoparticles on the supports This can lead characterization of plastic and elastic nuclei and surface deformation of Pt-based nanoparticles for the magic and unknown properties in respective to their catalytic activity As a result of these efforts, Pt, Pt-alloy, and non-Pt catalysts have been Figure 10 Evidences and testing of very high stability and reliability of the Pt based core-shell catalysts (a) The Pt mass activity A for the ORR as a function of the number of potential cycles n during fuel cell testing of the PtML/Pd/C electrocatalyst The limits of the potential cycle were 0.7 and 0.9 V (RHE), with a 30 s dwell time at 808 1C The results with Pt/C and Pt/ Ketjen carbon catalysts are shown for comparison b) The electrochemical surface area (SA) of the three catalysts as a function of number of potential cycles Reprinted with permission from: K Sasaki, H Naohara, Y Cai, Y.M Choi, P Liu, M.B Vukmirovic, J.X Wang, R.R Adzic, Core-protected platinum monolayer shell high-stability electrocatalysts for fuel-cell cathodes, Angew Chem Int Ed 49 (2010) 8602-8607 [215] Copyright © John Wiley & Sons, Inc All Rights Reserved standardized for the basic requirements of PEMFCs The issues of the durability and stability of Pt-based alloy cathode catalysts in PEMFCs have been studied [367,368] The development of methods of addressing the issues of durability and stability in Pt-based catalysts is of necessity to low-temperature FCs, PEMFCs and DMFCs Figure shows the important catalytic models of the use of as-prepared Pt nanoparticles on CeO2, ZrO2, and CeO2ZrO2 supports (in-situ TEM measurements and unpublished data from tests performed by the Toyota Company) It can be clearly observed that pure Pt nanoparticles can be supported inside and on the surfaces of CeO2, ZrO2, and CeO2-ZrO2 supports Therefore, which of these structures are the best choices for the design of effective, stable and 664 durable Pt-based catalysts must be evaluated from the viewpoint of electrocatalysis at the metal and oxide surfaces of the as-prepared catalysts In two works, the relations among the size, shape, support, composition, and oxidation-state effects in Pt nanoparticles with CeO2 and ZrO2 supports have been discussed, especially with respect to the low-temperature oxidation of CO and the potential applications of these materials in catalysis and various future fuel cells; particular attention has been paid to promising candidates for PEMFCs and DMFCs from the viewpoint of the oxidation-state effects of the Pt metal Recently, evidence has been widely found that Pt-Ru/CeO2/ CNT nanocomposites can serve as efficient electrocatalysts for DMFCs because of the advantages provided by the presence of CeO2 in the mixture catalysts for the significant enhancement of the MOR [369] The effect of CeO2 in Pt/ CeO2/CNT catalysts for CO electro-oxidation has also been studied for the improvement of PEMFC anodes [380,401] In a different study, a 20Pt–10CeO2/C catalyst exhibited superior ORR performance in comparison to a commercial 20Pt/C catalyst for potential application in lowtemperature fuel cells because of the oxygen-storage capacity of CeO2 and its ability to exchange oxygen rapidly with the buffer A 40Pt/C catalyst with wt% CeO2 exhibited the highest performance in air atmosphere In Figure 10, it is shown that the Pt mass activity of two commercial Pt/C catalysts is approximately three times smaller than that of a PtMLPd/C electrocatalyst After 60,000 potential cycles, the Pt/C (Pt loading: 0.133 mg/cm2) had lost almost 70% of its activity, compared witho20% for the PtML-Pd/C (Pt loading: 0.085 mg/cm2); the activity of the Pt/Ketjen black carbon (Pt loading: 0.3 mg/cm2) had fallen440% after only 10,000 cycles In particular, the Pt mass activity of the PtMLPd/C catalyst increased from the initial threefold enhancement to a fivefold enhancement over that of the Pt/C after 60,000 cycles This result demonstrates the superior stability and durability of the PtML-Pd/C resulting from the synergistic core-shell effect [370–372] Pt-Pd core-shell catalysts and Pd3Co-Pt with high and stable ORR catalytic activity have been developed for PEMFCs and DMFCs [386,388], and through the use of a Pt monolayer, a Pd-Au alloy electrocatalyst (10 at%) has been shown to exhibit a high ORR rate, leading to a large current density [387] Recently, the minimum levels of Pt loading that are necessary for the stable operation of DMFCs and DEFCs have been found to be relatively low and close to 0.15 and 0.05 mW μgPtÀ1, respectively In another study, nanocomposite electrodes based on pre-synthesized organically grafted platinum nanoparticles and CNTs have been investigated for use in FC devices The ORR selectivities and specific areas of porous electrodes related to the oxygen reduction reaction were confirmed to be between m2 gPtÀ1 and 310 m2 gPtÀ1 For the HOR and the ORR, the suitable load ranges of Ptbased catalysts corresponding to low-temperature FCs, PEMFCs and DMFCs have been confirmed Recently, PtSnO2 hybrid catalysts on nitrogen-doped CNTs have been shown to exhibit high catalytic activities and stability for low-temperature FCs [400] Both Pt/SnO2/CNT and Pt/ CeO2/CNT catalysts have shown application in the electrooxidation, which is a good way to reduce CO poisoning [400,401] Various Pt alloy (Pt-M, where M stands for Co, Fe, N.V Long et al Ni, or Pd) nanocrystals with cubic and octahedral morphologies have been prepared for high and stable ORR catalysis, especially Pt3Ni catalysts, which were found to have, at 0.9 V, values of 0.85 mA/cm2 Pt for the nanocubes [402] and 1.26 mA/cm2 Pt for the nanooctahedra; the octahedral Pt3Ni catalyst was found to have a high ORR mass activity of 0.44 A/mgPt As an example of a nanocomposite catalyst, a TiO2nanosheet-modified PtRu/C-based catalyst was prepared for use in a DMFC anode [404] After durability tests between 0.05 and 0.8 V at 50 mV s-1 for 2000 cycles, the ECSA and catalytic activity of the TiO2-nanosheet-modified PtRu/C were found to be higher than those of PtRu/C The ECSA of the TiO2-nanosheet-modified PtRu/C with TiO2/Pt = 0.25/1 was 63 m2 g-1, 1.6 times higher than the value of 38 m2 g-1 that was found for PtRu/C The MOR activity was 14.8 A (g PtRu)-1, almost 10 times higher than that of PtRu/C Pt/C FC anodes modified with RuO2 nanosheets have exhibited highly enhanced activity and stability [405] Generally, the use of oxide nanosheets or surface enrichment with oxides has led to higher stability against the degradation of PtRu/C catalysts and enhanced catalytic activity of Pt-based catalysts Conclusion In this review, we have discussed the highlights of the development of novel Pt-based mixture, alloy and coreshell catalysts with various supports for energy conversion in PEMFCs and DMFCs Nanoparticle and nanostructure models have been proposed for future investigations of the best Pt-based catalysts for PEMFCs and DMFCs The development of such Pt-based catalysts and the details of their electrocatalysis, mainly at the surfaces, still need to be studied We believe that there are some points of increasingly difficult controversy in the field Such controversy is important to the development of Pt-based catalysts of high catalytic activity and stability We have suggested that the shape-controlled synthesis of Pt-based alloy and core-shell nanostructures is one of the best method of reducing the high cost of PEMFCs and DMFCs by more than 50% with respect to PEMFCs and DMFCs that use pure Pt catalysts The core issue for the design of robust Pt-based catalysts with high catalytic activity but low costs that are attractive to scientists and researchers is to determine the particular atomic-composition ranges of Pt and other metals and the sizes, shapes and morphologies of the nanoparticles that are appropriate for particular ranges of catalytic activity and properties as well as particular potential practical applications The present research trend of the integration of pure Pt-based catalysts onto supports to improve their performance is especially well suited to energy materials and clean, green, and sustainable energy FC technologies Acknowledgments We would like thank the support of the National Foundation for Science and Technology Development (NAFOSTED), Vietnam, and the Research Foundation-Flanders (FWO), Cod FWO.2011.23, Belgium We would like thank Hanoi National University of Education for providing us with the support the development of Science and Nanotechnology Y Yang thanks the Century Program (One-Hundred-Talent The Development of Mixture, Alloy, and Core-Shell Nanocatalysts with Nanomaterial Supports for Energy Conversion Program) of the Chinese Academy of Sciences for special funding support This study was also supported in part by Funds from the National Natural Science Foundation of China (no 51071167, 51102266) Y Yang is also thankful for the support by Fund from Key Laboratory of Nanodevices and Applications, Suzhou Institute of Nano-Tech and NanoBionics, Chinese Academy of Sciences (no 12CS01) We thank Kyushu University and Nagoya Institute of Technology for providing us with significant financial support and help in the program of science and nanotechnology in Japan We are very grateful for the invaluable support from the Structural Ceramics Engineering Center, Shanghai Institute of Ceramics, Chinese Academy of Science, Dingxi Road 1295, Shanghai 200050, China References [1] B.C.H Steele, A Heinzel, Materials for fuel-cell technologies, Nature 414 (2001) 345–352 [2] K.Y Chan, J Ding, J Ren, S Cheng, K.Y Tsang, Supported mixed metal nanoparticles as electrocatalysts in low temperature fuel cells, J Mater Chem 14 (2004) 505–516 [3] R Borup, J Meyers, B Pivovar, Y.S Kim, R Mukundan, N Garland, D Myers, M Wilson, F Garzon, D Wood, P Zelenay, K More, K Stroh, T Zawodzinski, J Boncella, J.E McGrath, M Inaba, K Miyatake, M Hori, K Ota, Z Ogumi, S Miyata, A Nishikata, Z Siroma, Y Uchimoto, K Yasuda, K Kimijima, N Iwashita, Scientific Aspects of Polymer Electrolyte Fuel Cell Durability and Degradation, Chem Rev 107 (2007) 3899–4435 [4] H Bullinger, in: H Bullinger (Ed.), Technology Guide: Principles-Applications-Trends, Springer, Germany, 2009, pp 368–373 [5] J.S Spendelow, D.C Papageorgopoulos, Fuel Cells 11 (2011) 775–786 [6] S Litster, G McLean, PEM fuel cell electrodes, J Power Sources 130 (2004) 61–76 [7] O Okada, K Yokoyama, Fuel Cells (2001) 72–77 [8] J Kua, W.A Goddard III, Oxidation of Methanol on 2nd and 3rd Row Group VIII Transition Metals (Pt, Ir, Os, Pd, Rh, and Ru): Application to Direct Methanol Fuel Cells, J Am Chem Soc 121 (1999) 10928–10941 [9] V Mazumder, Y Lee, S Sun, Recent development of active nanoparticle catalysts for fuel cell reactions, Adv Func Mater 20 (2010) 1224–1231 [10] A.A Gewirth, M.S Thorum, Electroreduction of dioxygen for fuel-cell applications: Materials and challenges, Inorg Chem 49 (2010) 3557–3566 [11] S.A Cotton, Chemistry of Precious Metals, Chapman & Hall, UK, 1997 [12] C Salzemann, C Petit, Influence of hydrogen on the morphology of platinum and palladium nanocrystals, Langmuir 28 (2012) 4835–4841 [13] B.R Cuenya, Synthesis and catalytic properties of metal nanoparticles: Size, shape, support, composition, and oxidation state effects, Thin Solid Films 518 (2010) 3127–3150 [14] J Cookson, Nanoparticles, Controlled particle sizes are key to producing more effective and efficient materials, Platinum Metals Rev 56 (2012) 83–98 [15] S.J Peighambardoust, S Rowshanzamira, M Amjadi, Review of the proton exchange membranes for fuel cell applications, Int J Hydrogen Energy 35 (2010) 9349–9384 [16] A.S Aricò, P Bruce, B Scrosati, J Tarascon, W Schalkwijk, Nanostructured materials for advanced energy conversion and storage devices, Nat Mater (2005) 366–377 665 [17] V Mehta, J.S Cooper, Review and analysis of PEM fuel cell design and manufacturing, J Power Sources 114 (2003) 32–53 [18] A.B Yaroslavtsev, Y.A Dobrovolsky, N.S Shaglaeva, L.A Frolova, E.V Gerasimova, E.A Sanginov, Nanostructured materials for low-temperature fuel cells, Russ, Chem Rev 81 (2012) 191–220 [19] C Koenigsmanna, S.S Wong, One-dimensional noble metal electrocatalysts: a promising structural paradigm for direct methanol fuel cells, Energy Environ, Sci (2011) 1161–1176 [20] S Sharma, B.G Pollet, Support materials for PEMFC and DMFC electrocatalysts - A review, J Power Sources 208 (2012) 96–119 [21] S Du, Pt-based nanowires as electrocatalysts in proton exchange fuel cells, Int, J Low-Carbon Tech (2012) 44–54 [22] R.F Service, Platinumin fuel cells gets a helping hand, Science 315 (2007) 172 [23] M.K Debe, Electrocatalyst approaches and challenges for automotive fuel cells, Nature 486 (2012) 43–51 [24] A Rabis, P Rodriguez, T.J Schmidt, Perspective Electrocatalysis for Polymer Electrolyte Fuel Cells: Recent Achievements and Future Challenges, ACS Catal (2012) 864–890 [25] J.H Wee, K.Y Lee, S.H Kim, Fabrication methods for lowPt-loading electrocatalysts in proton exchange membrane fuel cell systems, J Power Sources 165 (2007) 667–677 [26] C Lamy, A Lima, V LeRhun, F Delime, C Coutanceau, J Léger, Recent advances in the development of direct alcohol fuel cells (DAFC), J Power Sources 105 (2002) 283–296 [27] S Wasmus, A Küver, Methanol oxidation and direct methanol fuel cells: a selective review, J Electroanal Chem 461 (1999) 14–31 [28] J Gellman, N Shukla, Nanocatalysis: More than speed, Nat Mater (2009) 87–88 [29] P Barbaro, C Bianchini, Catalysis for Sustainable Energy Production, Wiley-VCH Verlag GmbH and Co, KGaA, Weinheim, 2009 [30] M Hosokawa, K Nogi, M Naito, T Yokoyama, Nanoparticle Technology Handbook, Elsevier B.V, 2008 [31] X Huang, Y Li, Y Li, H Zhou, X Duan, Y Huang, Synthesis of PtPd Bimetal Nanocrystals with Controllable Shape, Composition, and Their Tunable Catalytic Properties, Nano Lett 12 (2012) 4265–4270 [32] V.L Nguyen, M Ohtaki, V.N Ngo, M.T Cao, M Nogami, Structure and morphology of platinum nanoparticles with critical new issues of low- and high-index facets, Adv Nat Sci: Nanosci Nanotechnol (2012) 025005 [33] M Subhramannia, V.K Pillai, Shape-dependent electrocatalytic activity of platinum nanostructures, J Mater Chem 18 (2008) 5858–5870 [34] G.A Somorjai, A.M Contreras, M Montano, R.M Rioux, Proc Natl Acad Sci 103 (2006) 10577–10583 [35] Y Li, G.A Somorjai, Nanoscale advances in catalysis and energy applications, Nano Lett 10 (2010) 2289–2295 [36] N.M Markoví, J.P.N Ross, Surface science studies of model fuel cell electrocatalysts, Surf Sci Rep 45 (2002) 117–229 [37] J Chen, C Menning, M Zellner, Monolayer bimetallic surfaces: Experimental and theoretical studies of trends in electronic and chemical properties, Surf Sci Rep 63 (2008) 201–254 [38] C.M Sánchez-Sánchez, J Solla-Gullón, F.J Vidal-lglesias, A Aldaz, V Montiel, E Herrero, Imaging Structure Sensitive Catalysis on Different Shape-Controlled Platinum Nanoparticles, J Am Chem Soc 132 (2010) 5622–5624 [39] S Basu, Recent Trends in Fuel Cell Science and Technology, New Delhi, Anamaya, Publishers, India, 2007 [40] W Vielstich, H.A Gasteiger, H Yokokawa, Handbook of Fuel Cells: Advances in Electrocatalysis, Materials, Diagnostics and Durability, John Wiley & Sons, United Kingdom, 2009 [41] J Erlebacher, Solid State Physics, in: H Ehrenreich, F Spaepen (Eds.), Elsvier Inc., Amsterdam, 2009, pp 77–141 [42] J.K Nørskov, J Rossmeisl, A Logadottir, L Lindqvist, J.R Kitchin, T Bligaard, H Jónsson, The origin of the 666 [43] [44] [45] [46] [47] [48] [49] [50] [51] [52] [53] [54] [55] [56] [57] [58] [59] [60] [61] [62] [63] [64] [65] N.V Long et al overpotential for oxygen reduction at a fuel cell cathode, J Phys Chem B 108 (2004) 17886–17892 J.K Nørskov, T Bligaard, J Rossmeisl, C.H Christensen, Density functional theory in surface chemistry and catalysis, Nat, Chem (2009) 37–46 C.J Cramer, D.G Truhlar, Density functional theory for transition metals and transition metal chemistry, Phys Chem Chem Phys 11 (2009) 10757–10816 S Harish, S Baranton, C Coutanceau, J Joseph, Microwave assisted polyol method for the preparation of Pt/C, Ru/C and PtRu/C nanoparticles and its application in electrooxidation of methanol, J Power Sources 214 (2012) 33–39 J Qi, L Jiang, Q Tang, S Zhu, S Wang, B Yi, G Sun, Synthesis of graphitic mesoporous carbons with different surface areas and their use in direct methanol fuel cells, Carbon 50 (2012) 2824–2831 B.M Quinn, C Dekker, S.G Lemay, Electrodeposition of Noble Metal Nanoparticles on Carbon Nanotubes, J Am Chem Soc 127 (2005) 6146–6147 W Chen, J Zhao, J.Y Lee, Z Liu, Microwave heated polyol synthesis of carbon nanotubes supported Pt nanoparticles for methanol electrooxidation, Mat Chem Phys 91 (2005) 124–129 G.F Álvarez, M Mamlouk, K Scott, An Investigation of Palladium Oxygen Reduction Catalysts for the Direct Methanol Fuel Cell, Int J Electrochem 2011 (2011) 1–12 B.D Adams, A Chen, The role of palladium in a hydrogen economy, Mater, Today 14 (2011) 282–289 M Shao, Palladium-based electrocatalysts for hydrogen oxidation and oxygen reduction reactions, J Power Sources 196 (2011) 2433–2444 E Antolini, Palladium in fuel cell catalysis, Energy Environ Sci (2009) 915–931 N.V Long, C.M Thi, M Nogami, M Ohtaki, Novel issues of morphology, size, and structure of Pt nanoparticles in chemical engineering: surface attachment, aggregation or agglomeration, assembly, and structural changes, New J Chem 36 (2012) 1320–1334 H Bullinger, Technology guide: Principles - applications trends, Springer, Germany, 2009 N Toshima, T Yonezawa, Bimetallic nanoparticles-novel materials for chemical and physical applications, New, J Chem 22 (1998) 1179–1201 E Antolini, Formation of carbon-supported PtM alloys for low temperature fuel cells: a review, Mater Chem Phys 78 (2003) 563–573 H.A Gasteiger, S.S Kocha, B Sompalli, F.T Wagner, Activity benchmarks and requirements for Pt, Pt-alloy, and non-Pt oxygen reduction catalysts for PEMFCs, Appl Catal., B 56 (2005) 9–35 Z Zhou, S Shang, N Tian, B Wu, N Zheng, B Xu, C Chen, H Wang, D Xiang, S Sun, Shape transformation from Pt nanocubes to tetrahexahedra with size near 10 nm, Electrochem Commun 22 (2012) 61–64 A Petrii, Pt-Ru electrocatalysts for fuel cells: A representative review, J Solid State Electrochem 12 (2008) 609–642 T.R Ralph, M.P Hogarth, Catalysis for Low Temperature Fuel Cells- Part I, Platinum Metals Rev 46 (2002) 3–14 T.R Ralph, M.P Hogarth, Catalysis for Low Temperature Fuel Cells- Part II, Platinum Metals Rev 46 (2002) 117–135 T.R Ralph, M.P Hogarth, Catalysis for Low Temperature Fuel Cells- Part III, Platinum Metals Rev 46 (2002) 146–164 K Park, J Choi, S Lee, C Pak, H Chang, Y Sung, PtRuRhNi nanoparticle electrocatalyst for methanol electrooxidation in direct methanol fuel cell, J Catalysis 224 (2004) 236–242 S Basri, S.K Kamarudin, W.R.W Daud, Z Yaakub, Nanocatalyst for direct methanol fuel cell (DMFC), Int J Hydrogen Energy 35 (2010) 7957–7970 J Kim, J Lee, Y Tak, Relationship between carbon corrosion and positive electrode potential in a proton-exchange [66] [67] [68] [69] [70] [71] [72] [73] [74] [75] [76] [77] [78] [79] [80] [81] [82] [83] [84] [85] [86] [87] membrane fuel cell during start/stop operation, J Power Sources 192 (2009) 674–678 C.B Murray, C.R Kagan, M.G Bawendi, Synthesis and Characterization of Monodisperse Nanocrystals and Close-Packed Nanocrystal Assemblies, Annu Rev Mater Sci 30 (2000) 545–610 Y Tan, Y Li, D Zhu, Noble metal nanoparticles, in: HS Nalwa (Ed.), Encyclopedia of nanoscience and nanotechnology, Vol 8, American Scientific Publishers, USA, 2004, pp 9–40 H Bönnemann, K.S Nagabhushana, Chemical synthesis of nanoparticles, in: HS Nalwa (Ed.), Encyclopedia of nanoscience and nanotechnology, Vol 1, American Scientific Publishers, USA, 2004, pp 777–813 AR Tao, S Habas, P Yang, Shape control of colloidal metal nanocrystals, Small (2008) 310–325 B.G Pollet, The use of ultrasound for the fabrication of fuel cell materials, Int J Hydrogen Energy 35 (2010) 11986–12004 H Wang, F Ye, C Wang, J Yang, Ultrafine Pt Nanoclusters for the Direct Methanol Fuel Cell Reactions, J Clust Sci 22 (2011) 173–181 Y Sun, L Zhuang, J Lu, X Hong, P Liu, Collapse in Crystalline Structure and Decline in Catalytic Activity of Pt Nanoparticles on Reducing Particle Size to nm, J Am Chem Soc 129 (2007) 15465–15467 Y Lu, W Chen, Sub-nanometre sized metal clusters: from synthetic challenges to the unique property discoveries, Chem Soc Rev 41 (2012) 3594–3623 K Yamamoto, T Imaoka, W Chun, O Enoki, H Katoh, M Takenaga, A Sonoi, Size-specific catalytic activity of platinum clusters enhances oxygen reduction reactions, Nat Chem (2009) 397–402 C Burda, X Chen, R Narayanan, M.A El-Sayed, Chemistry and properties of nanocrystals of different shapes, Chem Rev 105 (2005) 1025–1102 R Narayanan, M.A El-Sayed, Nanoscale advances in catalysis and energy applications, J Phys Chem B 109 (2005) 12663–12676 T.S Ahmadi, Z.L Wang, T.C Green, A Henglein, M.A ElSayed, Shape-controlled synthesis of colloidal platinum nanoparticles, Science 272 (1996) 1924–1926 Z.L Wang, Transmission electron microscopy of shapecontrolled nanocrystals and their assemblies, J Phys Chem B 104 (2000) 1153–1175 M Chen, B Wu, J Yang, N Zheng, Small AdsorbateAssisted Shape, Control of Pd and Pt Nanocrystals, Adv Mater 24 (2012) 862–879 C.V Rao, B Viswanathan, Monodispersed Platinum Nanoparticle Supported Carbon Electrodes for Hydrogen Oxidation and Oxygen Reduction in Proton Exchange Membrane Fuel Cells, J Phys Chem C 114 (2010) 8661–8667 L Calvillo, M.J Lázaro, E García-Bordejé, R Moliner, P.L Cabot, I Esparbé, E Pastor, J.J Quintana, Platinum supported on functionalized ordered mesoporous carbon as electrocatalyst for direct methanol fuel cells, J Power Sources 169 (2007) 59–64 H Huang, H Chen, D Sun, X Wang, Graphene nanoplate-Pt composite as a high performance electrocatalyst for direct methanol fuel cells, J Power Sources 204 (2012) 46–52 L Jorissen, V Gogel, J Kerres, J Garche, New membranes for direct methanol fuel cells, J Power Sources 105 (2002) 267–273 L Zhang, W Niu, G Xu, Seed-mediated growth of palladium nanocrystals: The effect of pseudo-halide thiocyanate ions, Nanoscale (2011) 678–682 W Niu, L Zhang, G Xu, Shape-Controlled Synthesis of Single-Crystalline Palladium Nanocrystals, ACS Nano (2010) 1987–1996 J Liu, D Xue, Nanosci Nano, Structures via Chemistry, Nanotechnol Lett (2011) 337–364 C Tsung, J.N Kuhn, W Huang, C Aliaga, L.I Hung, G.A Somorjai, P Yang, Sub-10 nm platinum nanocrystals with The Development of Mixture, Alloy, and Core-Shell Nanocatalysts with Nanomaterial Supports for Energy Conversion [88] [89] [90] [91] [92] [93] [94] [95] [96] [97] [98] [99] [100] [101] [102] [103] [104] [105] [106] size and shape control: Catalytic study for ethylene and pyrrole hydrogenation, J Am Chem Soc 131 (2009) 5816–5822 C Lee, H Chiou, Methanol-tolerant Pd nanocubes for catalyzing oxygen reduction reaction in H2SO4 electrolyte, Appl Catalysis, B 117-118 (2012) 204–211 M.H Shao, T Huang, P Liu, J Zhang, K Sasaki, M.B Vukmirovic, R.R Adzic, Palladium Monolayer and Palladium Alloy Electrocatalysts for Oxygen Reduction, Langmuir 22 (2006) 10409–10415 I.J Hsu, D.V Esposito, E.G Mahoney, A Black, J.G Chen, Particle shape control using pulse electrodeposition: Methanol oxidation as a probe reaction on Pt dendrites and cubes, J Power Sources 196 (2011) 8307–8312 Z Liu, L.M Gan, L Hong, W Chen, J.Y Lee, Carbonsupported Pt nanoparticles as catalysts for proton exchange membrane fuel cells, J Power Sources 139 (2005) 73–78 J Zeng, J.Y Lee, W Zhou, A more active Pt/carbon DMFC catalyst by simple reversal of the mixing sequence in preparation, J Power Sources 159 (2006) 509–513 S Cheong, J.D Watt, R.D Tilley, Shape control of platinum and palladium nanoparticles for catalysis, Nanoscale (2010) 2045–2053 X Gong, Y Yang, L Zhang, C Zou, P Cai, G Chen, S Huang, Controlled synthesis of Pt nanoparticles via seeding growth and their shape-dependent catalytic activity, J Colloid Interface Sci 352 (2101) 379-385 T Teranishi, M Hosoe, T Tanaka, M Miyake, Size control of monodispersed Pt nanoparticles and their 2D organization by electrophoretic deposition, J Phys Chem B 103 (1999) 3818–3827 H Song, F Kim, S Connor, G.A Somorjai, P Yang, Pt nanocrystals: Shape control and Langmuir-Blodgett monolayer formation, J Phys Chem B 109 (2005) 188–193 X Wang, W Wang, Z Qi, C Zhao, H Ji, Z Zhang, Electrochemical catalytic activities of nanoporous palladium rods for methanol electro-oxidation, J Power Sources 195 (2010) 6740–6747 H Yue, Y Zhao, X Ma, J Gong, Chem Ethylene glycol: properties, synthesis, and applications, Soc Rev 41 (2012) 4218–4244 ́ -Cigarroa, O Solorza-Feria, J.J Salvador-Pascual, S Citalan Kinetics of oxygen reduction reaction on nanosized Pd electrocatalyst in acid media, J Power Sources 172 (2007) 229–234 A Serov, T Nedoseykina, O Shvachko, C Kwak, Effect of precursor nature on the performance of palladium-cobalt electrocatalysts for direct methanol fuel cells, J Power Sources 195 (2010) 175–180 C.J DeSantis, A.C Sue, M.M Bower, S.E Skrabalak, SeedMediated Co-reduction: A Versatile Route to Architecturally Controlled Bimetallic Nanostructures, ACS Nano (2012) 2617–2628 C.M Sánchez-Sánchez, J Solla-Gullón, F.J Vidal-Iglesias, Antonio Aldaz, V Montiel, E Herrero, , Imaging Structure Sensitive Catalysis on Different Shape-Controlled Platinum Nanoparticles, J Am Chem Soc 132 (2010) 5622–5624 M Miyake, K Miyabayashi, Shape and size controlled Pt nanocrystals as novel model catalysts, Catal Surv Asia 16 (2012) 1–13 S Mostafa, F Behafarid, J.R Croy, L.K Ono, L Li, J.C Yang, A.I Frenkel, B.R Cuenya, Shape-dependent catalytic properties of Pt nanoparticles, J Am Chem Soc (2010) 15714–15719 Y Li, Q Liu, W Shen, Morphology-dependent nanocatalysis: metal particles, Dalton Trans 40 (2011) 5811–5826 N Tian, Z Zhou, S Sun, Y Ding, Z.L Wang, Synthesis of tetrahexahedral platinum nanocrystals with high-index facets and high electro-oxidation activity, Science 316 (2007) 732–735 667 [107] Z.L Wang, T.S Ahmad, M.A El-Sayed, Steps, ledges and kinks on the surfaces of platinum nanoparticles of different shapes, Surf Sci 380 (1997) 302–310 [108] S.W Lee, S Chen, J Suntivich, K Sasaki, R.R Adzic, Y ShaoHorn, Role of surface steps of Pt nanoparticles on the electrochemical activity for oxygen reduction, J Phys Chem Lett (2010) 1316–1320 [109] Y Shao-Horn, W.C Sheng, S Chen, P.J Ferreira, E.F Holby, D Morgan, Instability of supported platinum nanoparticles in low-temperature fuel cells, Top Catal 46 (2007) 285–305 [110] E Antolini, J Perez, The renaissance of unsupported nanostructured catalysts for low-temperature fuel cells: from the size to the shape of metal nanostructures, J Mater Sci 46 (2011) 4435–4457 [111] L.C Gontard, L Chang, C.J.D Hetherington, A.I Kirkland, D Ozkaya, R.E Dunin-Borkowski, Aberration-corrected imaging of active sites on industrial catalyst nanoparticles, Angew Chem 119 (2007) 3757–3759 [112] L.Y Chang, A.S Barnard, L.C Gontard, R.E DuninBorkowski, Resolving the structure of active sites on platinum catalytic nanoparticles, Nano Lett 10 (2010) 3073–3076 [113] C Yang, C Wan, C Lee, Palladium nanoparticles, Encycl Nanosci Nanotechnol (2004) 397–413 [114] B Lim, M Jiang, J Tao, P.H.C Camargo, Y Zhu, Y Xia, Shape-controlled synthesis of Pd nanocrystals in aqueous solutions, Adv Funct Mater 19 (2009) 189–200 [115] A.S Barnard, Mapping the shape and phase of palladium nanocatalysts, Catal Sci Technol (2012) 1485–1492 [116] S.L.Y Chang, A.S Barnard, C Dwyer, T.W Hansen, J.B Wagner, R.E Dunin-Borkowski, M Weyland, H Konishi, H Xu, Stability of Porous Platinum Nanoparticles: Combined In Situ TEM and Theoretical Study, J Phys Chem Lett (2012) 1106–1110 [117] S Barnard, H Konishi, H.F Xu, Morphology mapping of platinum catalysts over the entire nanoscale, Catal Sci Technol (2011) 1440–1448 [118] C Bianchini, P.K Shen, Palladium-Based Electrocatalysts for Alcohol Oxidation in Half Cells and in Direct Alcohol Fuel Cells, Chem Rev 109 (2009) 4183–4206 [119] F Taufany, C.J Pan, J Rick, H.L Chou, M.C Tsai, B.J Hwang, D.G Liu, J.F Lee, M.T Tang, Y.C Lee, C.I Chen, Kinetically Controlled Autocatalytic Chemical Process for Bulk Production of Bimetallic Core-Shell Structured Nanoparticles, ACS Nano (2011) 9370–9381 [120] G.A Tritsaris, J Rossmeisl, Methanol Oxidation on Model Elemental and Bimetallic Transition Metal Surfaces, J Phys Chem C 116 (2012) 11980–11986 [121] J Rossmeisl, W.G Bessler, Trends in catalytic activity for SOFC anode materials, Solid State Ionics 178 (31-32) (2008) 1694–1700 [122] P Mani, R Srivastava, P Strasser, Dealloyed Pt-Cu Core-Shell Nanoparticle, Electrocatalysts for Use in PEM Fuel Cell Cathodes, J Phys Chem C 112 (2008) 2770–2778 [123] S Koh, P Strasser, Electrocatalysis on Bimetallic Surfaces: Modifying Catalytic Reactivity for Oxygen Reduction by Voltammetric Surface Dealloying, J Am Chem Soc 129 (2007) 12624–12625 [124] R Gómez, A Fernández-Vega, J.M Feliu, A Aldaz, Hydrogen evolution on platinum single crystal surfaces: effects of irreversibly adsorbed bismuth and antimony on hydrogen adsorption and evolution on platinum (100), J Phys Chem 97 (1993) 4769–4776 [125] N.M Markovic, T.J Schmidt, V Stamenkovic, P.N Ross, Oxygen Reduction Reaction on Pt and Pt Bimetallic Surfaces: A Selective Review, Fuel Cells (2001) 105–116 [126] N.M Markovic, H.A Gasteiger, P.N Ross, Oxygen Reduction on Platinum Low-Index Single-Crystal Surfaces in Sulfuric Acid 668 [127] [128] [129] [130] [131] [132] [133] [134] [135] [136] [137] [138] [139] [140] [141] [142] [143] N.V Long et al Solution: Rotating Ring-Pt(hkl) Disk Studies, J Phys Chem 99 (1995) 3411–3415 N Furuya, S Koide, Hydrogen adsorption on platinum singlecrystal surfaces, Surf Sci 220 (1989) 18–28 J Kibsgaard, Y Gorlin, Z Chen, T.F Jaramillo, MesoStructured Platinum Thin Films: Active and Stable Electrocatalysts for the Oxygen Reduction Reaction, J Am Chem Soc 134 (2012) 7758–7765 J Lu, Z Li, S Jiang, P Shen, L Li, Nanostructured tungsten carbide/carbon composites synthesized by a microwave heating method as supports of platinum catalysts for methanol oxidation, J Power Sources 202 (2012) 56–62 X Bo, J Bai, J Ju, L Guo, Highly dispersed Pt nanoparticles supported on poly(ionic liquids) derived hollow carbon spheres for methanol oxidation, J Power Sources 196 (2011) 8360–8365 J.H Bang, Hollow graphitic carbon spheres for Pt electrocatalyst support in direct methanol fuel cell, Electrochim Acta 56 (2011) 8674–8679 D Sebastián, M.J Lázaro, I Suelves, R Moliner, V Baglio, A Stassi, A.S Aricò, The influence of carbon nanofiber support properties on the oxygen reduction behavior in proton conducting electrolyte-based direct methanol fuel cells, Int J Hydrogen Energy 37 (2012) 6253–6260 R Balgis, G.M Anilkumar, S Sago, T Ogi, K Okuyama, Nanostructured design of electrocatalyst support materials for high-performance PEM fuel cell application, J Power Sources 203 (2012) 26–33 N.V Long, M Ohtaki, T.D Hien, R Jalem, M Nogami, Synthesis and characterization of polyhedral and quasi-sphere nonpolyhedral Pt nanoparticles: effects of their various surface morphologies and sizes on electrocatalytic activity for fuel cell applications, J Nanopart Res 13 (2011) 5177–5191 N.V Long, M Ohtaki, M Nogami, T.D Hien, Effects of heat treatment and poly(vinylpyrrolidone) (PVP) polymer on electrocatalytic activity of polyhedral Pt nanoparticles towards their methanol oxidation, Colloid Polym Sci 289 (2011) 1373–1386 N.V Long, M Ohtaki, M Uchida, R Jalem, H Hirata, N D Chien, M Nogami, Synthesis and characterization of polyhedral Pt nanoparticles: Their catalytic property, surface attachment, self-aggregation and assembly, J Colloid Interface Sci 359 (2011) 339–350 N.V Long, N.D Chien, T Matsubara, H Hirata, G Lakshminarayana, M Nogami, The synthesis and characterization of platinum nanoparticles: a method of controlling the size and morphology, Nanotechnology 21 (2011) 035605 V.L Nguyen, N.D Chien, T Hayakawa, T Matsubara, M Ohtaki, M Nogami, Sharp cubic and octahedral morphologies of poly (vinylpyrrolidone)-stabilised platinum nanoparticles by polyol method in ethylene glycol: their nucleation, growth and formation mechanisms, J Exp Nanosci (2012) 133–149 V.L Nguyen, N.D Chien, H Hirata, M Ohtaki, T Hayakawa, M Nogami, Chemical synthesis and characterization of palladium nanoparticles, Adv Nat Sci Nanosci Nanotechnol (2010) 035012 P Strasser, S Koh, T Anniyev, J Greeley, K More, C Yu, Z Liu, S Kaya, D Nordlund, H Ogasawara, M.F Toney, A Nilsson, Lattice-strain control of the activity in dealloyed core-shell fuel cell catalysts, Nat Chem (2010) 454–460 B Wang, Recent development of non-platinum catalysts for oxygen reduction reaction, J Power Sources 152 (2005) 1–15 P.Holt-Hindle Chen, Platinum-Based Nanostructured Materials: Synthesis, Properties, and Applications, Chem Rev 110 (2010) 3767–3804 Z Peng, H Yang, Designer platinum nanoparticles: Control of shape, composition in alloy, nanostructure and electrocatalytic property, Nano Today (2009) 143–164 [144] J Chen, B Lim, E.P Lee, Y Xia, Shape-controlled synthesis of platinum nanocrystals for catalytic and electrocatalytic applications, Nano Today (2008) 81–95 [145] R Ferrando, J Jellinek, R.L Johnston, Nanoalloys: From Theory to Applications of Alloy Clusters and Nanoparticles, Chem Rev 108 (2008) 845–910 [146] L Carbone, P.D Cozzoli, Colloidal heterostructured nanocrystals: Synthesis and growth mechanisms, Nano Today (2010) 449–493 [147] H Yang, Platinum-Based Electrocatalysts with Core-Shell Nanostructures, Angew Chem Int Ed 50 (2011) 2674–2676 [148] M Min, C Kim, Y.I Yang, J Yi, H Lee, Surface-specific overgrowth of platinum on shaped gold nanocrystals, Phys Chem Chem Phys 11 (2009) 9759–9765 [149] Y Xia, Y Xiong, B Lim, S.E Skrabalak, Shape-Controlled Synthesis of Metal Nanocrystals: Simple Chemistry Meets Complex Physics? Angew Chem Int Ed 48 (2009) 60–103 [150] V.R Stamenkovic, B.S Mun, M Arenz, K.J.J Mayrhofer, C.A Lucas, G Wang, P.N Ross, N.M Markovic, Trends in electrocatalysis on extended and nanoscale Pt-bimetallic alloy surfaces, Nat Mater (2007) 241–247 [151] N.M Markovic, V Radmilovic, P.N Ross, Catalysis and Electrocatalysis at Nanoparticle Surfaces, Marcel Dekker, New York, 2003 [152] K.J.J Mayrhofer, B.B Blizanac, M Arenz, V.R Stamenkovic, P.N Ross, N.M Markovic, The Impact of Geometric and Surface Electronic Properties of Pt-Catalysts on the Particle Size Effect in Electrocatalysis, J Phys Chem B 109 (2005) 14433–14440 [153] F Maillard, S Schreier, M Hanzlik, E.R Savinova, S Weinkauf, U Stimming, Influence of particle agglomeration on the catalytic activity of carbon-supported Pt nanoparticles in CO monolayer oxidation, Phys Chem Chem Phys (2005) 385–393 [154] R.G Chaudhuri, S Paria, Core/Shell Nanoparticles: Classes, Properties, Synthesis Mechanisms, Characterization, and Applications, Chem Rev 112 (2012) 2373–2433 [155] N Toshima, H Yan, Y Shiraishi, in: B Corain, G Schmid, N Toshima (Eds.), Metal nanoclusters in catalysis and materials science: the issue of size control, Elsevier BV, 2008, pp 49–75 [156] H Jiang, Q Xu, Recent progress in synergistic catalysis over heterometallic nanoparticles, J Mater Chem 21 (2011) 13705–13725 [157] X Liu, X Liu, Bimetallic Nanoparticles: Kinetic Control Matters, Angew Chem Int Ed 51 (2012) 3311–3313 [158] C Hsieh, J Lin, Fabrication of bimetallic Pt–M (M=Fe, Co, and Ni) nanoparticle/carbon nanotube electrocatalysts for direct methanol fuel cells, J Power Sources 188 (2009) 347–352 [159] C Hsieh, W Chen, I Chen, A.K Roy, Deposition and activity stability of Pt–Co catalysts on carbon nanotube-based electrodes prepared by microwave-assisted synthesis, J Power Sources 199 (2012) 94–102 [160] D Mott, J Luo, P.N Njoki, Y Lin, L Wang, C.J Zhong, Synergistic activity of gold-platinum alloy nanoparticle catalysts, Catal Today 122 (2007) 378–385 [161] H Liu, C Song, L Zhang, J Zhang, H Wang, D.P Wilkinson, A review of anode catalysis in the direct methanol fuel cell, J Power Sources 155 (2006) 95–110 [162] P Lara, M Casanove, P Lecante, P Fazzini, K Philippot, B Chaudret, Segregation at a small scale: synthesis of coreshell bimetallic RuPt nanoparticles, characterization and solid state NMR studies, J Mater Chem 22 (2012) 3578–3584 [163] Y Gu, G Wu, X.F Hu, D.A Chen, T Hansen, H Loye, H J Ploehn, PAMAM-stabilized Pt-Ru nanoparticles for methanol electro-oxidation, J Power Sources 195 (2010) 425–434 [164] M Ueji, M Harada, Y Kimura, Synthesis of Pt/Ru bimetallic nanoparticles in high-temperature and high-pressure fluids, J Colloid Interf, Sci 322 (2008) 358–363 The Development of Mixture, Alloy, and Core-Shell Nanocatalysts with Nanomaterial Supports for Energy Conversion ́ [165] F.J Rodrıguez-Nieto, T.Y Morante-Catacora, C.R Cabrera, Sequential and simultaneous electrodeposition of Pt–Ru electrocatalysts on a HOPG substrate and the electro-oxidation of methanol in aqueous sulfuric acid, J Electroanal Chem 571 (2004) 115–126 [166] T.C Deivaraj, J.Y Lee, Preparation of carbon-supported PtRu nanoparticles for direct methanol fuel cell applications-a comparative study, J Power Sources 142 (2005) 43–49 [167] N Tsiouvaras, M.V Martínez-Huerta, R Moliner, M.J Lázaro, J.L Rodríguez, E Pastor, M.A Pa, J.L.G Fierro, CO tolerant PtRu-MoOx nanoparticles supported on carbon nanofibers for direct methanol fuel cells, J Power Sources 186 (2009) 299–304 [168] S Huang, C Yeh, Promotion of the electrocatalytic activity of a bimetallic platinum-ruthenium catalyst by repetitive redox treatments for direct methanol fuel cell, J Power Sources 195 (2010) 2638–2643 [169] V Díaz, M Ohanian, C.F Zinola, Kinetics of methanol electrooxidation on Pt/C and PtRu/C catalysts, Int J Hydrogen Energy 35 (2010) 10539–10546 [170] J.R.C Salgado, F Alcaide, G Álvarez, L Calvillo, M.J Lázaro, E Pastor, Pt-Ru electrocatalysts supported on ordered mesoporous carbon for direct methanol fuel cell, J Power Sources 195 (2010) 4022–4029 [171] F Su, C Poh, J Zeng, Z Zhong, Z Liu, J Lin, Pt nanoparticles supported on mesoporous carbon nanocomposites incorporated with Ni or Co nanoparticles for fuel cells, J Power Sources 205 (2012) 136–144 [172] J.M Sieben, M.M.E Duarte, Methanol, ethanol and ethylene glycol electro-oxidation at Pt and Pt-Ru catalysts electrodeposited over oxidized carbon nanotubes, Int J Hydrogen Energy 37 (2012) 9941–9947 [173] A Heinzela, V.M Barragán, A review of the state-of-the-art of the methanol crossover in direct methanol fuel cells, J Power Sources 84 (1999) 70–74 [174] W.C Choi, S.I Woo, Bimetallic Pt-Ru nanowire network for anode material in a direct-methanol fuel cell, J Power Sources 124 (2003) 420–425 [175] Z Wang, G Yin, Y Shao, B Yang, P Shi, P Feng, Electrochemical impedance studies on carbon supported PtRuNi and PtRu anode catalysts in acid medium for direct methanol fuel cell, J Power Sources 165 (2007) 9–15 [176] A.S Aricò, Z Poltarzewski, H Kim, A Morana, N Giordano, V Antonucci, Investigation of a carbon-supported quaternary Pt-Ru-Sn-W catalyst for direct methanol fuel cells, J Power Sources 55 (1995) 159–166 [177] Z Liu, X.Y Ling, B Guo, L Hong, J.Y Lee, Pt and PtRu nanoparticles deposited on single-wall carbon nanotubes for methanol electro-oxidation, J Power Sources 167 (2007) 272–280 [178] J Zhu, Y Su, F Cheng, J Chen, Improving the performance of PtRu/C catalysts for methanol oxidation by sensitization and activation treatment, J Power Sources 166 (2007) 331–336 [179] I.R.D Moraes, W.J.D Silva, S Tronto, J.M Rosolen, Carbon fibers with cup-stacked-type structure: An advantageous support for Pt-Ru catalyst in methanol oxidation, J Power Sources 160 (2006) 997–1002 [180] C Kim, H Kwon, I Song, Y Sung, W Chung, H Lee, Preparation of PtRu nanoparticles on various carbon supports using surfactants and their catalytic activities for methanol electro-oxidation, J Power Sources 171 (2007) 404–411 [181] D.M Han, Z.P Guo, Z.W Zhao, R Zeng, Y.Z Meng, D Shu, H K Liu, Polyoxometallate-stabilized Pt-Ru catalysts on multiwalled carbon nanotubes: Influence of preparation conditions on the performance of direct methanol fuel cells, J Power Sources 184 (2008) 361–369 [182] Z.X Liang, T.S Zhao, J.B Xu, Stabilization of the platinumruthenium electrocatalyst against the dissolution of ruthenium with the incorporation of gold, J Power Sources 185 (2008) 166–170 669 [183] A.S Polo, M.C Santos, R.F.B.D Souza, W.A Alves, Pt-Ru-TiO2 photoelectrocatalysts for methanol oxidation, J Power Sources 196 (2011) 872–876 [184] Y Li, L Zheng, S Liao, J Zeng, Pt-Ru/C catalysts synthesized by a two-stage polyol reduction process for methanol oxidation reaction, J Power Sources 196 (2011) 10570–10575 [185] L Zhang, J Kim, H Chen, F Nan, K Dudeck, R Liu, G A Botton, J Zhang, A novel CO-tolerant PtRu core-shell structured electrocatalyst with Ru rich in core and Pt rich in shell for hydrogen oxidation reaction and its implication in proton exchange membrane fuel cell, J Power Sources 196 (2011) 9117–9123 [186] C Alegre, L Calvillo, R Moliner, J.A González-Expósito, O Guillén-Villafuerte, M.V Martínez Huerta, E Pastor, M J Lázaro, Pt and PtRu electrocatalysts supported on carbon xerogels for direct methanol fuel cells, J Power Sources 196 (2011) 4226–4235 [187] A Velázquez-Palenzuela, F Centellas, J.A Garrido, C Arias, R.M Rodríguez, E Brillas, P Cabot, Kinetic analysis of carbon monoxide and methanol oxidation on high performance carbon-supported Pt–Ru electrocatalyst for direct methanol fuel cells, J Power Sources 196 (2011) 3503–3512 [188] E.A Franceschini, G.A Planes, F.J Williams, G.J.A.A SolerIllia, H.R Corti, Mesoporous Pt and Pt/Ru alloy electrocatalysts for methanol oxidation, J Power Sources 196 (2011) 1723–1729 [189] D Kaplan, M Alon, L Burstein, Yu Rosenberg, E Peled, Study of core-shell platinum-based catalyst for methanol and ethylene glycol oxidation, J Power Sources 196 (2011) 1078–1083 [190] S en, F en, G Gửkaaỗ, Preparation and characterization of nano-sized Pt–Ru/C catalysts and their superior catalytic activities for methanol and ethanol oxidation, Phys Chem Chem Phys 13 (2011) 6784–6792 [191] S Alayoglu, B Eichhorn, Rh-Pt Bimetallic Catalysts: Synthesis, Characterization, and Catalysis of Core-Shell, Alloy, and Monometallic Nanoparticles, J Am Chem Soc 130 (2008) 17479–17486 [192] J.Y Park, Y Zhang, S.H Joo, Y Jung, G.A Somorjai, Size effect of RhPt bimetallic nanoparticles in catalytic activity of CO oxidation: Role of surface segregation, Catal Today 181 (2012) 133–137 [193] S Alayoglu, A.U Nilekar, M Mavrikakis, B Eichhorn, Ru-Pt core-shell nanoparticles for preferential oxidation of carbon monoxide in hydrogen, Nat Mater (2008) 333–338 [194] J Zhang, K Sasaki, E Sutter, R.R Adzic, Stabilization of Platinum Oxygen-Reduction Electrocatalysts Using Gold Clusters, Science 315 (2007) 220–222 [195] B Ballarin, M Gazzano, D Tonelli, Effects of different additives on bimetallic Au-Pt nanoparticles electrodeposited onto indium tin oxide electrodes, Electrochimica Acta 55 (2010) 6789–6795 [196] S.S Kumar, K.L.N Phani, Exploration of unalloyed bimetallic Au–Pt/C nanoparticles for oxygen reduction reaction, J Power Sources 187 (2009) 19–24 [197] S.T Kuk, A Wieckowski, Methanol electrooxidation on platinum spontaneously deposited on unsupported and carbon-supported ruthenium nanoparticles, J Power Sources 141 (2005) 1–7 [198] Z Liu, X Ling, X Su, J Lee, L Gan, Preparation and characterization of Pt/C and Pt-Ru/C electrocatalysts for direct ethanol fuel cells, J Power Sources 149 (2005) 1–7 [199] P Hernández-Fernández, S Rojas, P Ocón, A de Frutos, J M Figueroa, P Terreros, M.A Peña, J.L.G Fierro, Relevance of the nature of bimetallic PtAu nanoparticles as electrocatalysts for the oxygen reduction reaction in the presence of methanol, J Power Sources 177 (2008) 9–16 [200] Y Yamauchi, A Tonegawa, M Komatsu, H Wang, L Wang, Y Nemoto, N Suzuki, K Kuroda, Electrochemical Synthesis of 670 [201] [202] [203] [204] [205] [206] [207] [208] [209] [210] [211] [212] [213] [214] [215] [216] [217] [218] [219] N.V Long et al Mesoporous Pt-Au Binary Alloys with Tunable Compositions for Enhancement of Electrochemical Performance, J Am Chem Soc 134 (2012) 5100–5109 H Zhang, T Watanabe, M Okumura, M Haruta, N Toshima, Catalytically highly active top gold atom on palladium nanocluster, Nat Mater 11 (2012) 49–52 B Fang, B.N Wanjala, X Hu, J Last, R Loukrakpam, J Yin, J Luo, C.J Zhong, Proton exchange membrane fuel cells with nanoengineered AuPt catalysts at the cathode, J Power Sources 196 (2011) 659–665 N.V Long, N.D Chien, M Uchida, T Matsubara, R Jalem, M Nogami, Directed and random self-assembly of Pt-Au nanoparticles, Mater Chem Phys 124 (2010) 1193–1197 J Wang, G Yin, H Liu, R Li, R.L Flemming, X Sun, Carbon nanotubes supported Pt-Au catalysts for methanol-tolerant oxygen reduction reaction: A comparison between Pt/Au and PtAu nanoparticles, J Power Sources 194 (2009) 668–673 S Yan, S Zhang, Methanol electrooxidation on carbon supported Aucore-Ptshell nanoparticles synthesized by an epitaxial growth method, Int, J Hydrogen Energy 37 (2012) 9636–9644 R Lin, H Zhang, T Zhao, C Cao, D Yang, J Ma, Investigation of Au@Pt/C electro-catalysts for oxygen reduction reaction, Electrochim Acta 62 (2012) 263–268 R.R Adzic, J Zhang, K Sasaki, M.B Vukmirovic, M Shao, J X Wang, A.U Nilekar, M Mavrikakis, J.A Valerio, F Uribe, Platinum Monolayer Fuel Cell Electrocatalysts, Top Catal 46 (2007) 249–262 A.U Nilekar, K Sasaki, C.A Farberow, R.R Adzic, M Mavrikakis, Mixed-Metal Pt Monolayer Electrocatalysts with Improved CO Tolerance, J Am Chem Soc 133 (2011) 18574–18576 H Park, T Jeon, J.H Jang, S.J Yoo, K Lee, Y Cho, K Choi, Y Cho, c Namgee Jung, Y Chung, Y Sung, Hydrogen Oxidation Reaction Activity of Sub-Monolayer Pt-Shell/Pd-Core Nanoparticles, J Electrochem Soc 160 (2013) H62–H66 J Kim, S.W Lee, C Carlton, Y Shao-Horn, Pt-Covered Multiwall Carbon Nanotubes for Oxygen Reduction in Fuel Cell Applications, J Phys Chem Lett (2011) 1332–1336 Y Ando, K Sasaki, R Adzic, Electrocatalysts for methanol oxidation with ultra low content of Pt and Ru, Electrochem Commun 11 (2009) 1135–1138 R Wang, H Wang, B Wei, W Wang, Z Lei, Carbon supported Pt-shell modified PdCo-core with electrocatalyst for methanol oxidation, Int J Hydrogen Energy 35 (2010) 10081–10086 A.U Nilekar, S Alayoglu, B Eichhorn, M Mavrikakis, Preferential CO Oxidation in Hydrogen: Reactivity of Core-Shell Nanoparticles, J Am Chem Soc 132 (2010) 7418–7428 J Zhang, M.B Vukmirovic, K Sasaki, A.U Nilekar, M Mavrikakis, R.R Adzic, Mixed-Metal Pt Monolayer Electrocatalysts for Enhanced Oxygen Reduction Kinetics, J Am Chem Soc 127 (2005) 12480–12481 K Sasaki, H Naohara, Y Cai, Y.M Choi, P Liu, M B Vukmirovic, J.X Wang, R.R Adzic, Core-Protected Platinum Monolayer Shell High-Stability Electrocatalysts for FuelCell Cathodes, Angew Chem Int Ed 49 (2010) 8602–8607 N Kristian, X Wang, Ptshell-Aucore/C electrocatalyst with a controlled shell thickness and improved Pt utilization for fuel cell reactions, Electrochem Commun 10 (2008) 12–15 J Zhang, F.H.B Lima, M.H Shao, K Sasaki, J.X Wang, J Hanson, R.R Adzic, Platinum Monolayer on Nonnoble Metal-Noble Metal Core-Shell Nanoparticle Electrocatalysts for O2 Reduction 109 (2005) 22701–22704 J.K Nørskov, J Rossmeisl, A Logadottir, L Lindqvist, J Kitchin, T Bligaard, H Jónsson, J Phys Chem B, Origin of the Overpotential for Oxygen Reduction at a Fuel-Cell Cathode 108 (2004) 17887–17892 J.K Nørskova, F Abild-Pedersen, F Studt, T Bligaard, Density functional theory in surface chemistry and catalysis, Proc Natl Acad Sci U S A 108 (2011) 937–943 [220] D Wang, H.L Xin, H Wang, Y Yu, E Rus, D.A Muller, F J DiSalvo, H.D Abruña, Facile Synthesis of Carbon-Supported Pd-Co Core-Shell Nanoparticles as Oxygen Reduction Electrocatalysts and Their Enhanced Activity and Stability with Monolayer Pt Decoration, Chem Mater 24 (2012) 2274–2281 [221] M Oezaslan, P Strasser, Activity of dealloyed PtCo3 and PtCu3 nanoparticle electrocatalyst for oxygen reduction reaction in polymer electrolyte membrane fuel cell, J Power Sources 196 (2011) 5240–5249 [222] G Marcua, R Totha, P Srivastava, P Strasser, Preparation, characterization and degradation mechanisms of PtCu alloy nanoparticles for automotive fuel cells, J Power Sources 208 (2012) 288–295 [223] H Zhu, X Li, F Wang, Synthesis and characterization of Cu@Pt/C core-shell structured catalysts for proton exchange membrane fuel cell, Int J Hydrogen Energy 36 (2011) 9151–9154 [224] S Chen, H Zhang, L Wu, Y Zhao, C Huang, M Ge, Z Liu, Controllable synthesis of supported Cu–M (M =Pt, Pd, Ru, Rh) bimetal nanocatalysts and their catalytic performances, J Mater Chem 22 (2012) 9117–9122 [225] Y Chen, F Yang, Y Dai, W Wang, S Chen, Ni@Pt Core-Shell Nanoparticles: Synthesis, Structural and Electrochemical Properties, J Phys Chem C 112 (2008) 1645–1649 [226] R Wang, C Xu, X Bi, Y Ding, Nanoporous surface alloys as highly active and durable oxygen reduction reaction electrocatalysts, Energy Environ Sci (2012) 5281–5286 [227] S Bhlapibul, K Pruksathorn, P Piumsomboon, The effect of the stabilizer on the properties of a synthetic Nicore-Ptshell catalyst for PEM fuel cells, Renewable Energy 41 (2012) 262–266 [228] K Zhang, Q Yue, G Chen, Y Zhai, L Wang, H Wang, J Zhao, J Liu, J Jia, H Li, Effects of Acid Treatment of PtÀNi Alloy Nanoparticles@Graphene on the Kinetics of the Oxygen Reduction Reaction in Acidic and Alkaline Solutions, J Phys Chem C 115 (2011) 379–389 [229] H Yang, W Vogel, C Lamy, N Alonso-Vante, Structure and Electrocatalytic Activity of Carbon-Supported Pt-Ni Alloy Nanoparticles Toward the Oxygen Reduction Reaction, J Phys Chem B 108 (2004) 11024–11034 [230] D Wang, P Zhao, Y Li, General preparation for Pt-based alloy nanoporous nanoparticles as potential nanocatalysts, Sci Rep (2011) 1–5 [231] H Wu, D Wexler, G Wang, H Liu, Facile preparation and electrochemical behavior of Pt100ÀxCox(111) single-crystal electrodes in 0.1 M HClO4, J Solid State Electrochem 16 (2012) 1105–1110 [232] M Wakisaka, Y Hyuga, K Abe, H Uchida, M Watanabe, Performance of Pt-Co/C prepared by the selective deposition of Co on Pt as a cathode in PEMFCs, Electrochem, Commun 13 (2011) 317–320 [233] S Seo, H Joh, H Kim, S Moon, Electrocatalysis of oxygen reduction on carbon-supported Pt-Co nanoparticles with low Pt content, J Power Sources 163 (2006) 403–408 [234] F.H.B Lima, J.F.R de Castro, L.G.R.A Santos, E.A Ticianelli, Electrocatalysis of oxygen reduction on carbon-supported Pt– Co nanoparticles with low Pt content, J Power Sources 190 (2009) 293–300 [235] J Qian, W Wei, X Huang, Y Tao, K Chen, X Tang, A study of different polyphosphazene-coated carbon nanotubes as a Pt– Co catalyst support for methanol oxidation fuel cell, J Power Sources 210 (2012) 345–349 [236] A Stassi, I Gatto, G Monforte, V Baglio, E Passalacqua, V Antonucci, A Aricò, The effect of thermal treatment on structure and surface composition of PtCo electro-catalysts for application in PEMFCs operating under automotive conditions, J Power Sources 208 (2012) 35–45 [237] N Travitsky, T Ripenbein, D Golodnitsky, Y Rosenberg, L Burshtein, E Peled, Pt-, PtNi- and PtCo-supported The Development of Mixture, Alloy, and Core-Shell Nanocatalysts with Nanomaterial Supports for Energy Conversion [238] [239] [240] [241] [242] [243] [244] [245] [246] [247] [248] [249] [250] [251] [252] [253] [254] [255] catalysts for oxygen reduction in PEM fuel cells, J Power Sources 161 (2006) 782–789 B.N Wanjala, R Loukrakpam, J Luo, P.N Njoki, D Mott, C Zhong, M Shao, L Protsailo, T Kawamura, Thermal Treatment of PtNiCo Electrocatalysts: Effects of Nanoscale Strain and Structure on the Activity and Stability for the Oxygen Reduction Reaction, J Phys Chem C 114 (2010) 17580–17590 U.A Paulus, A Wokaun, G Scherer, T.J Schmidt, V Stamenkovic, V Radmilovic, N.M Markovic, P.N Ross, Oxygen Reduction on Carbon-Supported Pt-Ni and Pt-Co Alloy Catalysts, J Phys Chem B 106 (2002) 4181–4191 J.G Chen, C.A Menning, M.B Zellner, Monolayer bimetallic surfaces: Experimental and theoretical studies of trends in electronic and chemical properties, Surf Sci Rep 63 (2008) 201–254 J.A Rodriguez, Physical and chemical properties of bimetallic surfaces, Surf Sci Rep 24 (1996) 223–287 Q Fua, T Wagnera, Interaction of nanostructured metal overlayers with oxide surfaces, Surf Sci Rep 62 (2007) 431–498 F Godínez-Salomón, M Hallen-López, O Solorza-Feria, Enhanced electroactivity for the oxygen reduction on Ni@Pt core-shell nanocatalysts, Int, J Hydrogen Energy 37 (2012) 14902–14910 Z Niu, D Wang, R Yu, Q Peng, Y Li, Highly branched Pt-Ni nanocrystals enclosed by stepped surface for methanol oxidation, Chem Sci (2012) 1925–1929 W Li, Z Chen, L Xu, Y Yan, A solution-phase synthesis method to highly active Pt-Co/C electrocatalysts for proton exchange membrane fuel cell, J Power Sources 195 (2010) 2534–2540 P Hernández-Fernández, M Montiel, P Ocón, J.L.G Fierro, H Wang, H.D Abra, S Rojas, Effect of Co in the efficiency of the methanol electrooxidation reaction on carbon supported Pt, J Power Sources 195 (2010) 7959–7967 J Do, Y Chen, M Lee, Effect of thermal annealing on the properties of Corich core–Ptrich shell/C oxygen reduction electrocatalyst, J Power Sources 172 (2007) 623–632 L.H.S Gasparotto, E.G Ciapina, E.A Ticianelli, G TremiliosiFilho, Electrodeposition of PVA-protected PtCo electrocatalysts for the oxygen reduction reaction in H2SO4, J Power Sources 197 (2012) 97–101 E Bertin, S Garbarino, A Ponrouch, D Guay, Synthesis and characterization of PtCo nanowires for the electro-oxidation of methanol, J Power Sources 206 (2012) 20–28 C.V Rao, J Parrondo, S.L Ghatty, B Rambabu, High temperature polymer electrolyte membrane fuel cell performance of PtxCoy/C cathodes, J Power Sources 195 (2010) 3425–3430 B.P Vinayan, R.Imran Jafri, N Rupali Nagar, K Rajalakshmi, S Sethupathi, Ramaprabhu, Catalytic activity of platinum– cobalt alloy nanoparticles decorated functionalized multiwalled carbon nanotubes for oxygen reduction reaction in PEMFC, Int J Hydrogen Energy 37 (2012) 412–421 X Wang, J Stover, V Zielasek, L Altmann, K Thiel, K AlShamery, M Baumer, H Borchert, J Parisi, J Kolny-Olesiak, Colloidal Synthesis and Structural Control of PtSn Bimetallic Nanoparticles, Langmuir 27 (2011) 11052–11061 T.S Almeida, L.M Palma, P.H Leonello, C Morais, K B Kokoh, A.R.D Andrade, An optimization study of PtSn/C catalysts applied to direct ethanol fuel cell: Effect of the preparation method on the electrocatalytic activity of the catalysts, J Power Sources 215 (2012) 53–62 A.N Golikand, S.M Golabi, M.G Maragheh, L Irannejad, Electrocatalytic oxidation of methanol on (Pb) lead modified by Pt, Pt-Ru and Pt-Sn microparticles dispersed into poly(o-phenylenediamine) film, J Power Sources 145 (2005) 116–123 W Li, Q Xin, Y Yan, Nanostructured Pt–Fe/C cathode catalysts for direct methanol fuel cell: The effect of catalyst composition, Int J Hydrogen Energy 35 (2010) 2530–2538 671 [256] J Luo, L Han, N.N Kariuki, L Wang, D Mott, C Zhong, T He, Synthesis and Characterization of Monolayer-Capped PtVFe Nanoparticles with Controllable Sizes and Composition, Chem Mater 17 (2005) 5282–5290 [257] X Li, L An, X Wang, F Li, R Zou, D Xia, Supported sub-5nm Pt-Fe intermetallic compounds for electrocatalytic application, J Mater Chem 22 (2012) 6047–6052 [258] B Fang, J Luo, P.N Njoki, R Loukrakpam, D Mott, B Wanjala, X Hu, C Zhong, Nanostructured PtVFe catalysts: Electrocatalytic performance in proton exchange membrane fuel cells, Electrochem Commu 11 (2009) 1139–1141 [259] B Fang, J Luo, Y Chen, B.N Wanjala, R Loukrakpam, J Hong, J Yin, X Hu, P Hu, C Zhong, Nanoengineered PtVFe/C Cathode Electrocatalysts in PEM Fuel Cells: Catalyst Activity and Stability, ChemCatChem (2011) 583–593 [260] A.R Malheiro, J Perez, H.M Villullas, Surface structure and electronic properties of Pt-Fe/C nanocatalysts and their relation with catalytic activity for oxygen reduction, J Power Sources 195 (2010) 3111–3118 [261] V Baglio, A.S Aricò, A Stassi, C D’Urso, A Di Blasi, A M Castro Luna, V Antonucci, Investigation of Pt-Fe catalysts for oxygen reduction in low temperature direct methanol fuel cells, J Power Sources 159 (2006) 900–904 [262] A.R Malheiro, J Perez, H.M Villullas, Dependence on composition of electronic properties and stability of Pt-Fe/ C catalysts for oxygen reduction, J Power Sources 195 (2010) 7255–7258 [263] C.K Poh, Z Tian, J Gao, Z Liu, J Lin, Y.P Feng, F Su, Nanostructured trimetallic Pt/FeRuC, Pt/NiRuC, and Pt/ CoRuC catalysts for methanol electrooxidation, J Mater Chem 22 (2012) 13643–13652 [264] T Cochell, A Manthiram, Pt@PdxCuy/C Core-Shell Electrocatalysts for Oxygen Reduction Reaction in Fuel Cells, Langmuir 28 (2012) 1579–1587 [265] J.J Salvador-Pascual, V Collins-Martínez, A López-Ortíz, O Solorza-Feria, Low Pt content on the Pd45Pt5Sn50 cathode catalyst for PEM fuel cells, J Power Sources 195 (2010) 3374–3379 [266] J Zhao, K Jarvis, P Ferreira, A Manthiram, Performance and stability of Pd-Pt-Ni nanoalloy electrocatalysts in proton exchange membrane fuel cells, J Power Sources 196 (2011) 4515–4523 [267] J Zeng, J Lee, Ruthenium-free, carbon-supported cobalt and tungsten containing binary & ternary Pt catalysts for the anodes of direct methanol fuel cells, Int J Hydrogen Energy 32 (2007) 4389–4396 [268] A Ignaszak, C Song, W Zhu, Y Wang, J Zhang, A Bauer, R Baker, V Neburchilov, S Ye, S Campbell, Carbon– Nb0.07Ti0.93O2 composite supported Pt-Pd electrocatalysts for PEM fuel cell oxygen reduction reaction, Electrochim Acta 75 (2012) 220–228 [269] H Wang, R Wang, H Li, Q Wang, J Kang, Z Lei, Facile synthesis of carbon-supported pseudo-core@shell PdCu@Pt nanoparticles for direct methanol fuel cells, Int J Hydrogen Energy 36 (2011) 839–848 [270] V Raghuveer, A Manthiram, A.J Bard, J Phys Chem, B, PdCo-Mo Electrocatalyst for the Oxygen Reduction Reaction in Proton Exchange Membrane Fuel Cells 109 (2005) 22909–22912 [271] E Antolini, Platinum-based ternary catalysts for low temperature fuel cells Part I Preparation methods and structural characteristics, Appl Catal., B 74 (2007) 324–336 [272] E Antolini, Platinum-based ternary catalysts for low temperature fuel cells: Part II Electrochemical properties, Appl Catal., B 74 (2007) 337–350 [273] G Zhang, Z Shao, W Lu, F Xie, H Xiao, X Qin, B Yi, Coreshell Pt modified Pd/C as an active and durable electrocatalyst for the oxygen reduction reaction in PEMFCs, Appl Catal., B 132-33 (2013) 183–194 672 [274] C Koenigsmann, M.E Scofield, H Liu, S.S Wong, Designing Enhanced One-Dimensional Electrocatalysts for the Oxygen Reduction Reaction: Probing Size- and CompositionDependent Electrocatalytic Behavior in Noble Metal Nanowires, J Phys Chem Lett (2012) 3385–3398 [275] L Liu, G Samjeske, S Nagamatsu, O Sekizawa, K Nagasawa, S Takao, Y Imaizumi, T Yamamoto, T Uruga, Y Iwasawa, Enhanced Oxygen Reduction Reaction Activity and Characterization of Pt–Pd/C Bimetallic Fuel Cell Catalysts with Pt-Enriched Surfaces in Acid Media, J Phys Chem C 116 (2012) 23453–23464 [276] V Neburchilov, J Martin, H Wang, J Zhang, A review of polymer electrolyte membranes for direct methanol fuel cells, J Power Sources 169 (2007) 221–238 [277] M Jiang, B Lim, J Tao, P.H.C Camargo, C Ma, Y Zhu, Y Xia, Epitaxial overgrowth of platinum on palladium nanocrystals, Nanoscale (2010) 2406–2411 [278] C Koenigsmann, A.C Santulli, K Gong, M.B Vukmirovic, W Zhou, E Sutter, S.S Wong, R.R Adzic, Enhanced Electrocatalytic Performance of Processed, Ultrathin, Supported PdPt Core0Shell Nanowire Catalysts for the Oxygen Reduction Reaction, J Am Chem Soc 133 (2011) 9783–9795 [279] Z Zhang, J Hui, Z Guo, Q Yu, B Xu, X Zhang, Z Liu, C Xu, J Gao, X Wang, Solvothermal synthesis of Pt-Pd alloys with selective shapes and their enhanced electrocatalytic activities, Nanoscale (2012) 2633–2639 [280] C.J Serpell, J Cookson, D Ozkaya, P.D Beer, Core@shell bimetallic nanoparticle synthesis via anion coordination, Nat Chem (2011) 478–483 [281] B Lim, M Jiang, P.H.C Camargo, E.C Cho, J Tao, X Lu, Y Zhu, Y Xia, Pd-Pt Bimetallic Nanodendrites with High Activity for Oxygen Reduction, Science 324 (2009) 1302–1305 [282] J.W Hong, S.W Kang, B.S Choi, D Kim, S.B Lee, S.W Han, Controlled Synthesis of Pd-Pt Alloy Hollow Nanostructures with Enhanced Catalytic Activities for Oxygen Reduction, ACS Nano (2012) 2410–2419 [283] A Lebon, A García-Fuente, A Vega, F Aguilera-Granja, Hydrogen interaction in Pd-Pt alloy nanoparticles, J Phys Chem C 116 (2012) 126–133 [284] G Li, W Lu, Y Luo, M Xia, C Chai, X Wang, Synthesis and Characterization of Dendrimer-Encapsulated Bimetallic Core-Shell PdPt Nanoparticles, Chin J Chem 30 (2012) 541–546 [285] Y Xing, Y Cai, M.B Vukmirovic, W Zhou, H Karan, J X Wang, R.R Adzic, Enhancing Oxygen Reduction Reaction Activity via PdÀAu Alloy Sublayer Mediation of Pt Monolayer Electrocatalysts, J Phys Chem Lett (2010) 3238–3242 [286] F Tao, M.E Grass, Y Zhang, D.R Butcher, J.R Renzas, Z Liu, J.Y Chung, B.S Mun, M Salmeron, G.A Somorjai, ReactionDriven Restructuring of Rh-Pd and Pt-Pd Core-Shell Nanoparticles, Science 322 (2008) 932–934 [287] M Yamauchi, H Kobayashi, H Kitagawa, Hydrogen Storage Mediated by Pd and Pt Nanoparticles, Chem Phys Chem 10 (2009) 2566–2576 [288] H Kobayashi, M Yamauchi, H Kitagawa, Y Kubota, K Kato, M Takata, Atomic-Level PdÀPt Alloying and Largely Enhanced Hydrogen-Storage Capacity in Bimetallic Nanoparticles Reconstructed from Core/Shell Structure by a Process of Hydrogen Absorption/Desorption, J Am Chem Soc 132 (2010) 5576–5577 [289] D.A Slanaca, L Li, A Mayoral, M.J Yacaman, A Manthiram, K.J Stevenson, K.P Johnston, Atomic resolution structural insights into PdPt nanoparticle–carbon interactions for the design of highly active and stable electrocatalysts, Electrochim Acta 64 (2012) 35–45 [290] S.M Alia, K.O Jensen, B.S Pivovar, Y Yan, Platinum-Coated Palladium Nanotubes as Oxygen Reduction Reaction Electrocatalysts, ACS Catal (2012) 858–863 N.V Long et al [291] V.L Nguyen, M Ohtaki, T Matsubara, M.T Cao, M Nogami, New Experimental Evidences of Pt–Pd Bimetallic Nanoparticles with Core–Shell Configuration and Highly Fine-Ordered Nanostructures by High-Resolution Electron Transmission Microscopy, J Phys Chem C 22 (2012) 12265–12274 [292] N.V Long, T Asaka, T Matsubara, M Ohtaki, M Nogami, M, Shape-controlled synthesis of Pt–Pd core–shell nanoparticles exhibiting polyhedral morphologies by modified polyol method, Acta Mater 59 (2011) 2901–2907 [293] N.V Long, T.D Hien, T Asaka, M Ohtaki, M Nogami, Synthesis and characterization of Pt–Pd nanoparticles with core-shell morphology: Nucleation and overgrowth of the Pd shells on the as-prepared and defined Pt seeds, J Alloys Compd 509 (2011) 7702–7709 [294] N.V Long, M Ohtaki, T.D Hien, J Randy, M Nogami, A comparative study of Pt and Pt–Pd core–shell nanocatalysts, Electrochim Acta 56 (2011) 9133–9143 [295] N.V Long, T.D Hien, T Asaka, M Ohtaki, M Nogami, Synthesis and characterization of Pt–Pd alloy and core-shell bimetallic nanoparticles for direct methanol fuel cells (DMFCs): Enhanced electrocatalytic properties of wellshaped core-shell morphologies and nanostructures, Int J Hydrogen Energy 36 (2011) 8478–8491 [296] Y Chu, Z Wang, Z Jiang, D Gu, G Yin, Facile synthesis of hollow spherical sandwich PtPd/C catalyst by electrostatic self-assembly in polyol solution for methanol electrooxidation, J Power Sources 203 (2012) 17–25 [297] W Wang, Q Huang, J Liu, Z Zou, M Zhao, W Vogel, H Yang, Surface and structure characteristics of carbonsupported Pd3Pt1 bimetallic nanoparticles for methanoltolerant oxygen reduction reaction, J Catalysis 266 (2009) 156–163 [298] D Jung, S Bae, S Kim, K Nahm, P Kim, Effect of the Pt precursor on the morphology and catalytic performance of Pt-impregnated on Pd/C for the oxygen reduction reaction in polymer electrolyte fuel cells, Int J Hydrogen Energy 36 (2011) 9115–9122 [299] S.S Mahapatra, A Dutta, J Datta, Temperature dependence on methanol oxidation and product formation on Pt and Pd modified Pt electrodes in alkaline medium, Int J Hydrogen Energy 36 (2011) 14873–14883 [300] F Alcaide, G Álvarez, P.L Cabot, H Grande, O Miguel, A Querejeta, Testing of carbon supported Pd-Pt electrocatalysts for methanol electrooxidation in direct methanol fuel cells, Int, J Hydrogen Energy 36 (2011) 4432–4439 [301] M.A Mahmoud, F Saira, M.A El-Sayed, Experimental Evidence For The Nanocage Effect In Catalysis With Hollow Nanoparticles, Nano Lett 10 (2010) 3764–3769 [302] J Xu, J Yang, J.Y Lee, M Saeys, Design of an Oxygen Reduction Catalyst for Direct Methanol Fuel Cells, Ind Eng Chem Res 49 (2010) 10251–10253 [303] Q.T Trinh, J Yang, J.Y Lee, M Saeys, Computational and experimental study of the Volcano behavior of the oxygen reduction activity of PdM@PdPt/C (M =Pt, Ni, Co, Fe, and Cr) core–shell electrocatalysts, J Catalysis 291 (2012) 26–35 [304] D Cheng, W Wang, Tailoring of Pd-Pt bimetallic clusters with high stability for oxygen reduction reaction, Nanoscale (2012) 2408–2415 [305] Z Yang, Y Zhang, J Wang, S Ma, First-principles study on the Ni@Pt12 Ih core–shell nanoparticles: A good catalyst for oxygen reduction reaction, Phys Lett A 375 (2011) 3142–3148 [306] R Huang, Y Wen, Z Zhu, S Sun, Two-Stage Melting in CoreShell Nanoparticles: An Atomic-Scale Perspective, J Phys Chem C 116 (2012) 11837–11841 [307] R Huang, Y Wen, Z Zhu, S Sun, Pt-Pd Bimetallic Catalysts: Structural and Thermal Stabilities of Core–Shell and Alloyed Nanoparticles, J Phys Chem C 116 (2012) 8664–8671 The Development of Mixture, Alloy, and Core-Shell Nanocatalysts with Nanomaterial Supports for Energy Conversion [308] Y Wang, N Toshima, Preparation of Pd-Pt Bimetallic Colloids with Controllable Core/Shell Structures, J Phys Chem B 27 (1997) 5301–5306 [309] J.R Croy, S Mostafa, L Hickman, H Heinrich, B.R Cuenya, Bimetallic Pt-Metal catalysts for the decomposition of methanol: Effect of secondary metal on the oxidation state, activity, and selectivity of Pt, Appl Catal., A 350 (2008) 207–216 [310] N Menzel, E Ortel, R Kraehnert, P Strasser, Electrocatalysis Using Porous Nanostructured Materials, Chem Phys Chem 13 (2012) 1385–1394 [311] M Nogami, R Koike, R Jalem, G Kawamura, Y Yang, Y Sasaki, Synthesis of Porous Single-Crystalline Platinum Nanocubes Composed of Nanoparticles, J Phys Chem Lett (2010) 568–571 [312] J Luo, L Wang, D Mott, P.N Njoki, Y Lin, T He, Z Xu, B N Wanjana, I.I.S Lim, C Zhong, Core/Shell Nanoparticles as Electrocatalysts for Fuel Cell Reactions, Adv Mater 20 (2008) 4342–4347 [313] C Zhong, J Luo, B Fang, B.N Wanjala, P.N Njoki, R Loukrakpam, J Yin, Nanostructured catalysts in fuel cells, Nanotechnology 21 (2010) 062001 [314] B Fang, B.N Wanjala, J Yin, R Loukrakpam, J Luo, X Hu, J Last, C Zhong, Electrocatalytic performance of Pt-based trimetallic alloy nanoparticle catalysts in proton exchange membrane fuel cells, Int J Hydrogen Energy 37 (2012) 4627–4632 [315] D.V Esposito, S.T Hunt, Y.C Kimmel, J.G Chen, A New, Class of Electrocatalysts for Hydrogen Production from Water Electrolysis: Metal Monolayers Supported on Low-Cost Transition Metal Carbides, J Am Chem Soc 134 (2012) 3025–3033 [316] M.D Obradović, S.Lj Gojković, N.R Elezović, P Ercius, V R Radmilović, Lj.D Vračar, N.V Krstajić, The kinetics of the hydrogen oxidation reaction on WC/Pt catalyst with low content of Pt nano-particles, J Electroanal Chem 671 (2012) 24–32 [317] S.H Joo, J.Y Park, C Tsung, Y Yamada, P Yang, G.A Somorjai, Thermally stable Pt/mesoporous silica core–shell nanocatalysts for high-temperature reactions, Nat Mater (2009) 126–131 [318] H Naohara, T Yoshimoto, N Toshima, Platinum nanoparticles protected by a perfluorinated sulfonic acid copolymer: Preparation, nano-network formation and electrocatalytic activity, J Power Sources 195 (2010) 1051–1053 [319] H Naohara, Y Okamoto, N Toshima, Preparation and electrocatalytic activity of palladium-platinum core-shell nanoalloys protected by a perfluorinated sulfonic acid ionomer, J Power Sources 196 (2011) 7510–7513 [320] F Sonsudin, T Masuda, K Ikeda, H Naohara, K Uosaki, Effect of Coating by Perfluorosulfonated Ionomer Film on Electrochemical Behaviors of Pt(111) Electrode in Acidic Solutions, Chem Lett 39 (2010) 286–287 [321] F Tao, M.E Grass, Y Zhang, D.R Butcher, F Aksoy, S Aloni, V Altoe, S Alayoglu, J.R Renzas, C.K Tsung, Z Zhu, Z Liu, M Salmeron, G.A Somorjai, Evolution of Structure and Chemistry of Bimetallic Nanoparticle Catalysts under Reaction Conditions, J Am Chem Soc 132 (2010) 8697–8703 [322] Y.N Wu, S.J Liao, H.F Guo, X.Y Hao, High-performance Pd@PtRu/C catalyst for the anodic oxidation of methanol prepared by decorating Pd/C with a PtRu shell, J Power Sources 224 (2013) 66–71 [323] Y Wu, S Liao, Z Liang, L Yang, R Wang, High-performance core–shell PdPt@Pt/C catalysts via decorating PdPt alloy cores with Pt, J Power Sources 194 (2009) 805–810 [324] H Wang, C Xu, F Cheng, M Zhang, S Wang, S.P Jiang, Pd/ Pt core–shell nanowire arrays as highly effective electrocatalysts for methanol electrooxidation in direct methanol fuel cells, Electrochem Commun 10 (2008) 1575–1578 [325] V Selvaraj, M Alagar, I Hamerton, Electrocatalytic properties of monometallic and bimetallic nanoparticlesincorporated polypyrrole films for electro-oxidation of methanol, J Power Sources 160 (2006) 940948 673 [326] B Fỗclar, A Bayrakỗeken, Erolu, Effect of Pd loading in Pd-Pt bimetallic catalysts doped into hollow core mesoporous shell carbon on performance of proton exchange membrane fuel cells, J Power Sources 193 (2009) 17–23 [327] L Wang, Y Nemoto, Y Yamauchi, Direct Synthesis of SpatiallyControlled Pt-on-Pd Bimetallic Nanodendrites with Superior Electrocatalytic Activity, J Am Chem Soc 133 (2011) 9674–9677 [328] A Lebon, A García-Fuente, A Vega, F Aguilera-Granja, Hydrogen insertion in Pd core/Pt shell cubo-octahedral nanoparticles, Phys Rev B 83 (2011) 125427–125434 [329] B.A Kakade, T Tamaki, H Ohashi, T Yamaguchi, Highly Active Bimetallic PdPt and CoPt Nanocrystals for Methanol Electro-oxidation, J Phys Chem C 116 (2012) 7464–7470 [330] Y Liu, M Chi, V Mazumder, K.L More, S Soled, J.D Henao, S Sun, Composition-Controlled Synthesis of Bimetallic PdPt Nanoparticles and Their Electro-oxidation of Methanol, Chem Mater 23 (2011) 4199–4203 [331] W He, J Liu, Y Qiao, Z Zou, X Zhang, D.L Akins, H Yang, Simple preparation of Pd-Pt nanoalloy catalysts for methanoltolerant oxygen reduction, J Power Sources 195 (2010) 1046–1050 [332] W Wang, D Zheng, C Du, Z Zou, X Zhang, B Xia, H Yang, D.L Akins, Carbon-supported Pd-Co bimetallic nanoparticles as electrocatalysts for the oxygen reduction reaction, J Power Sources 167 (2007) 243–249 [333] P.P Lopes, E.A Ticianelli, H Varela, Potential oscillations in a proton exchange membrane fuel cell with a Pd-Pt/C anode, J Power Sources 196 (2011) 84–89 [334] J Jang, C Pak, Y Kwon, Ultrasound-assisted polyol synthesis and electrocatalytic characterization of PdxCo alloy and core–shell nanoparticles, J Power Sources 201 (2012) 179–183 [335] W Tang, G Henkelman, Charge redistribution in core-shell nanoparticles to promote oxygen reduction, J Chem Phys 130 (2009) 194504–194506 [336] J.X Wang, H Inada, L Wu, Y Zhu, Y Choi, P Liu, W.P Zhou, R.R Adzic, Oxygen Reduction on Well-Defined CoreÀShell Nanocatalysts: Particle Size, Facet, and Pt Shell Thickness Effects, J Am Chem Soc 131 (2009) 17298–17302 [337] N.M Sánchez-Padilla, S.M Montemayor, F.J Rodríguez Varela, An easy route to synthesize novel Fe3O4@Pt core-shell nanostructures with high electrocatalytic activity, J New Mater Electrochem Syst 15 (3) (2012) 171–179 [338] S Lin, C Shen, D Lua, C Wang, H Gao, Synthesis of Pt nanoparticles anchored on graphene-encapsulated Fe3O4 magnetic nanospheres and their use as catalysts for methanol oxidation, Carbon 53 (2013) 112–119 [339] V.M Dhavale, S Kurungot, Tuning the Performance of LowPt Polymer Electrolyte Membrane Fuel Cell Electrodes Derived from Fe2O3@Pt/C Core–Shell Catalyst Prepared by an in Situ Anchoring Strategy, J Phys Chem C 116 (2012) 7318–7326 [340] E Proietti, F Jaouen, M Lefèvre, N Larouche, J Tian, J Herranz, J.P Dodelet, Iron-based cathode catalyst with enhanced power density in polymer electrolyte membrane fuel cells, Nat Commun (2011) 416 [341] M Choi, C Han, I Kim, J An, J Lee, H Lee, J Shim, Electrochemical Characterization of Nano-Sized Pd-Based Catalysts as Cathode Materials in Direct Methanol Fuel Cells, J Nanosci Nanotechnol 11 (2011) 738–741 [342] M Choi, C Han, I Kim, J Lee, H Lee, J Shim, Effect of the Nanosized TiO2 Particles in Pd/C Catalysts As Cathode Materials in Direct Methanol Fuel Cells, J Nanosci Nanotechnol 11 (2011) 6420–6424 [343] C.R Hammond, CRC Handbook of Chemistry and Physics, Taylor and Francis Group, LLC, in: D.R Lide, W.M Haynes (Eds.), 90th edn., 2010, p [344] J Rossmeisl, P Ferrin, G.A Tritsaris, A.U Nilekar, S Koh, S E Bae, S.R Brankovic, P Strasser, M Mavrikakis, Energy Environ, Sci (2012) 8335–8342 674 [345] J.R Croy, S Mostafa, J Liu, Y Sohn, H Heinrich, B.R Cuenya, Support Dependence of MeOH Decomposition Over Size-Selected Pt Nanoparticles, Catal Lett 119 (2007) 209–216 [346] B.Y Xia, B Wang, H.B Wu, Z Liu, X Wang, X.Wen Lou, Sandwich-structured TiO2–Pt–graphene ternary hybrid electrocatalysts with high efficiency and stability, J Mater Chem 22 (2012) 16499–16505 [347] K Bakhmutsky, N.L Wieder, M Cargnello, B Galloway, P Fornasiero, R.J Gorte, A Versatile Route to Core–Shell Catalysts: Synthesis of Dispersible M@Oxide (M=Pd, Pt; Oxide=TiO2, ZrO2) Nanostructures by Self-Assembly, Chem Sus Chem (2012) 140–148 [348] R Wang, H He, J Wang, L Liu, H Dai, Shape-regulation: An effective way to control CO oxidation activity over noble metal catalysts, Catal Today 201 (2013) 68–78 [349] C.K Krishnan, K Nakamura, H Hirata, M Ogura, Pt/CeO2– ZrO2 present in the mesopores of SBA-15 - a better catalyst for CO oxidation, Phys Chem Chem Phys 12 (2010) 7513–7520 [350] N Hickey, P Fornasiero, M Graziani, Renewable Resources and Renewable Energy, in: M Graziani, P Fornasiero (Eds.), A Global Challenge, CRC Press, 2006, pp 225–272 [351] Y Yamada, C Tsung, W Huang, Z Huo, S.E Habas, T Soejima, C.E Aliaga, G.A Somorjai, P Yang, Nanocrystal bilayer for tandem catalysis, Nat Chem (2011) 372–376 [352] S.B Kalidindi, B.R Jagirdar, Nanocatalysis and Prospects of Green Chemistry, ChemSusChem (2012) 65–75 [353] J Yang, X Chen, F Ye, C Wang, Y Zheng, J Yang, Core-shell CdSe@Pt nanocomposites with superior electrocatalytic activity enhanced by lateral strain effect, J Mater Chem 21 (2011) 9088–9094 [354] D.Z Mezalira, M Bron, High stability of low Pt loading high surface area electrocatalysts supported on functionalized carbon nanotubes, J Power Sources 231 (2012) 113–121 [355] Z Yan, W Wei, J Xie, S Meng, X Lü, J Zhu, An ion exchange route to produce WO3 nanobars as Pt electrocatalyst promoter for oxygen reduction reaction, J Power Sources 222 (2013) 218–224 [356] S Maass, F Finsterwalder, G Frank, R Hartmann, C Merten, Carbon support oxidation in PEM fuel cell cathodes, J Power Sources 176 (2008) 444–451 [357] N Rajalakshmi, H Ryu, M.M Shaijumona, S Ramaprabhua, Performance of polymer electrolyte membrane fuel cells with carbon nanotubes as oxygen reduction catalyst support material, J Power Sources 140 (2005) 250–257 [358] G Bender, M Angelo, K Bethune, R Rocheleau, Quantitative analysis of the performance impact of low-level carbon monoxide exposure in proton exchange membrane fuel cells, J Power Sources 228 (2013) 159–169 [359] T.T Ngo, T.L Yu, H Lin, Influence of the composition of isopropyl alcohol/water mixture solvents in catalyst ink solutions on proton exchange membrane fuel cell performance, J Power Sources 225 (2013) 293–303 [360] P Parthasarathy, A.V Virkar, Effect of stress on dissolution/ precipitation of platinum: Implications concerning core– shell catalysts and cathode degradation in proton exchange membrane fuel cells, J Power Sources 196 (2011) 9204–9212 [361] X Yu, S Ye, Recent advances in activity and durability enhancement of Pt/C catalytic cathode in PEMFC: Part I Physico-chemical and electronic interaction between Pt and carbon support, and activity enhancement of Pt/C catalyst, J Power Sources 172 (2007) 133–144 [362] X Yu, S Ye, Recent advances in activity and durability enhancement of Pt/C catalytic cathode in PEMFC: Part II: Degradation mechanism and durability enhancement of carbon supported platinum catalyst, J Power Sources 172 (2007) 145–154 N.V Long et al [363] Y Shao, G Yin, Y Gao, Understanding and approaches for the durability issues of Pt-based catalysts for PEM fuel cell, J Power Sources 171 (2007) 558–566 [364] K.J.J Mayrhofer, J.C Meier, S.J Ashton, G.K.H Wiberg, F Kraus, M Hanzlik, M Arenz, Fuel cell catalyst degradation on the nanoscale, Electrochem Commun 10 (2008) 1144–1147 [365] L Brandão, J Rodrigues, L.M Madeira, A Mendes, Methanol crossover reduction by Nafion modification with palladium composite nanoparticles: Application to direct methanol fuel cells, Int, J Hydrogen Energy 35 (2010) 11561–11567 [366] C.W.B Bezerra, L Zhang, H Liu, K Lee, A.L.B Marques, E P Marques, H Wang, J Zhang, A review of heat-treatment effects on activity and stability of PEM fuel cell catalysts for oxygen reduction reaction, J Power Sources 173 (2007) 891–908 [367] H.R Colón-Mercado, B.N Popov, Stability of platinum based alloy cathode catalysts in PEM fuel cells, J Power Sources 155 (2006) 253–263 [368] B.R Cuenya, Metal Nanoparticle Catalysts Beginning to Shapeup, Acc Chem Res., Article ASAP, DOI: 10.1021/ar300226p [369] Z Sun, X Wang, Z Liu, H Zhang, P Yu, L Mao, PtÀRu/CeO2/ Carbon Nanotube Nanocomposites: An Efficient Electrocatalyst for Direct Methanol Fuel Cells, Langmuir 26 (2010) 12383–12389 [370] M.B Vukmirovic, S.T Bliznakov, K Sasaki, J.X Wang, R R Adzic, Electrochem Soc, Interface 20 (2011) 33–40 [371] A Brouzgoua, S.Q Song, P Tsiakarasa, Low and non-platinum electrocatalysts for PEMFCs: Current status, challenges and prospects, Appl Catal., B 127 (2012) 371–388 [372] X Cheng, F Volatron, E Pardieu, A Borta, G Carrot, C Reynaud, M Mayne, M Pinault, A Etcheberry, H Perez, Nanocomposite electrodes based on pre-synthesized organically grafted platinum nanoparticles and carbon nanotubes III: Determination of oxygen reduction reaction selectivity and specific area of porous electrode related to the oxygen reduction reaction ranging from m2 gPtÀ1 to 310 m2 gPtÀ1, Electrochim Acta 89 (2013) 1–12 [373] N.V Long, M Ohtaki, M Nogami, Control of Morphology of Pt Nanoparticles and Pt-Pd Core-Shell Nanoparticles, J Novel Carbon Resource Sci.Kuyshu Univ (2011) 40–44 [374] S Khanal, G Casillas, J.J Velazquez-Salazar, A Ponce, M Jose-Yacaman, Atomic Resolution Imaging of Polyhedral PtPd Core–Shell Nanoparticles by Cs-Corrected STEM, J Phys Chem C 116 (2012) 23596–23602 [375] H Zhang, M Jin, H Liu, J Wang, M.J Kim, D Yang, Z Xie, J Liu, Y Xia, Facile Synthesis of Pd–Pt Alloy Nanocages and Their Enhanced Performance for Preferential Oxidation of CO in Excess Hydrogen, ACS Nano (2011) 8212–8222 [376] Y Dai, Y Liu, S Chen, Pt-W bimetallic alloys as CO-tolerant PEMFC anode catalysts, Electrochim Acta 89 (2013) 744–748 [377] J Greeley, M Mavrikakis, Alloy catalysts designed from first principles, Nat Mater (2004) 810–815 [378] A Stassi, I Gatto, V Baglio, E Passalacqua, A.S Aricò, Investigation of Pd-based electrocatalysts for oxygen reduction in PEMFCs operating under automotive conditions, J Power Sources 222 (2013) 390–399 [379] E.O Jardim, M Gonỗalves, S Rico-Francộs, A SepỳlvedaEscribano, J Silvestre-Albero, Superior performance of mutiwall carbon nanotubes as support of Pt-based catalysts for the preferential CO oxidation: Effect of ceria addition, Appl Catal., B 113-114 (2012) 72–78 [380] H Yuan, D Guo, X Li, L Yuan, W Zhu, L Chen, X Qiu, The effect of CeO2 on Pt/CeO2/CNT catalyst for CO electrooxidation, Fuel Cells (2009) 121–127 [381] D Lim, W Lee, H Lee, Catal Highly Dispersed and Nanosized Pt-based Electrocatalysts for Low-Temperature Fuel Cells, Surv Asia 12 (2008) 310–325 [382] C.K Poh, Z Tian, J Gao, Z Liu, J Lin, Y.P Feng, F Su, Nanostructured trimetallic Pt/FeRuC, Pt/NiRuC, and Pt/ The Development of Mixture, Alloy, and Core-Shell Nanocatalysts with Nanomaterial Supports for Energy Conversion [383] [384] [385] [386] [387] [388] [389] [390] [391] [392] [393] [394] [395] [396] [397] [398] CoRuC catalysts for methanol electrooxidation, J Mater Chem 22 (2012) 13643–13652 Z Zhou, Z Shao, X Qin, X Chen, Z Wei, B Yi, Durability study of Pt–Pd/C as PEMFC cathode catalyst, Int J Hydrogen Energy 35 (2010) 1719–1726 F Kadirgan, S Beyhan, T Atilan, Preparation and characterization of nano-sized Pt–Pd/C catalysts and comparison of their electro-activity toward methanol and ethanol oxidation, Int J Hydrogen Energy 34 (2009) 4312–4320 P.P Wells, E.M Crabb, C.R King, R Wiltshire, B Billsborrow, D Thompsett, A.E Russell, Preparation, structure, and stability of Pt and Pd monolayer modified Pd and Pt electrocatalysts, Phys Chem Chem Phys 11 (2009) 5773–5781 K Sasaki, J.X Wang, H Naohara, N Marinkovic, K More, H Inada, R.R Adzic, Recent advances in platinum monolayer electrocatalysts for oxygen reduction reaction: Scale-up synthesis, structure and activity of Pt shells on Pd cores, Electrochim Acta 55 (2010) 2645–2652 Y Xing, Y Cai, M.B Vukmirovic, W Zhou, H Karan, J.X Wang, R.R Adzic, Enhancing Oxygen Reduction Reaction Activity via Pd-Au Alloy Sublayer Mediation of Pt Monolayer Electrocatalysts, J Phys Chem Lett (2010) 3238–3242 J.X Wang, H Inada, L Wu, Y Zhu, Y Choi, P Liu, W Zhou, R R Adzic, Oxygen Reduction on Well-Defined CoreÀShell Nanocatalysts: Particle Size, Facet, and Pt Shell Thickness Effects, J Am Chem Soc 131 (2009) 17298–17302 J Zhao, A Manthiram, Preleached Pd-Pt-Ni and Binary Pd-Pt Electrocatalysts for Oxygen Reduction Reaction in Proton Exchange Membrane Fuel Cells 101 (2011) 660–668Appl Catal., B 101 (2011) 660–668 E Antolini, J.R.C Salgado, E.R Gonzalez, The stability of Pt– M (M =first row transition metal) alloy catalysts and its effect on the activity in low temperature fuel cells: A literature review and tests on a Pt–Co catalyst, J Power Sources 160 (2006) 957–968 H.X Zhang, C Wang, J.Y Wang, J.J Zhai, W.B Cai, CarbonSupported PdÀPt Nanoalloy with Low Pt Content and Superior Catalysis for Formic Acid Electro-oxidation, J Phys Chem C 114 (2010) 6446–6451 C.R Hammond, The Elements, CRC Handbook of Chemistry and Physics, in: D.R Lide, W.M Haynes (Eds.), Taylor and Francis Group, LLC, 90th edn., 2010, pp 4–25 Y Feng, L Bi, Z Liu, D Kong, Z Yu, Significantly enhanced electrocatalytic activity for methanol electro-oxidation on Ag oxide-promoted PtAg/C catalysts in alkaline electrolyte, J Catal 290 (2012) 18–25 S.J Hwang, S.J Yoo, S Jang, T Lim, S.A Hong, S Kim, Ternary Pt-Fe-Co Alloy Electrocatalysts Prepared by Electrodeposition: Elucidating the Roles of Fe and Co in the Oxygen Reduction Reaction, J Phys Chem C 115 (2011) 2483–2488 S.V Selvaganesh, P Sridhar, S Pitchumani, A.K Shukla, A Durable Graphitic-Carbon Support for Pt and Pt3Co Cathode Catalysts in Polymer Electrolyte Fuel Cells, J Electrochem Soc 160 (2013) F49–F59 A Bonakdarpour, J Wenzel, D.A Stevens, S Sheng, T L Monchesky, R Löbel, R.T Atanasoski, A.K Schmoeckel, G.D Vernstrom, M.K Debe, J.R Dahn, Studies of Transition Metal Dissolution from Combinatorially Sputtered, Nanostructured Pt1ÀxMx (M = Fe, Ni; 0oxo1) Electrocatalysts for PEM Fuel Cells, J Electrochem Soc 152 (2005) A61–A72 M Oezaslan, F Hasché, P Strasser, Oxygen Electroreduction on PtCo3, PtCo and Pt3Co Alloy Nanoparticles for Alkaline and Acidic PEM Fuel Cells, J Electrochem Soc 159 (2012) B394–B405 W He, M Chen, Z Zou, Z Li, X Zhang, S Jin, D.J You, C Pak, H Yang, Oxygen reduction on Pd3Pt1 bimetallic nanoparticles highly loaded on different carbon supports, Appl Catal., B 97 (2010) 347–353 675 [399] D.A Slanac, L Li, A Mayoral, M.J Yacaman, A Manthiram, Ke.J Stevenson, K.P Johnston, Atomic resolution structural insights into PdPt nanoparticle-carbon interactions for the design of highly active and stable electrocatalysts, Electrochim Acta 64 (2012) 35–45 [400] Y Chen, J Wang, X Meng, Y Zhong, R Li, X Sun, S Ye, S Knights, Atomic layer deposition assisted Pt-SnO2 hybrid catalysts on nitrogen-doped CNTs with enhanced electrocatalytic activities for low temperature fuel cells, Int, J Hydrogen Energy 36 (2011) 11085–11092 [401] H Yuan, D Guo, X Li, L Yuan, W Zhu, L Chen, X Qiu, The effect of CeO2 on Pt/CeO2/CNT catalyst for CO electrooxidation, Fuel Cells (2009) 121–127 [402] J Wu, A Gross, H Yang, Shape and Composition-Controlled Platinum Alloy Nanocrystals Using Carbon Monoxide as Reducing Agent, Nano Lett 11 (2011) 798–802 [403] A Velázquez-Palenzuela, E Brillas, C Arias, F Centellas, J A Garrido, R.M Rodríguez, P Cabot, Structural analysis of carbon-supported Ru-decorated Pt nanoparticles synthesized using forced deposition and catalytic performance toward CO, methanol, and ethanol electro-oxidation, J Catal 298 (2013) 112–121 [404] T Saida, N Ogiwara, W Sugimoto, Y Takasu, Titanium Oxide Nanosheet, Modified PtRu/C Electrocatalyst for Direct Methanol Fuel Cell Anodes, J Phys Chem C 114 (2010) 13390–13396 405 T Saida, W Sugimoto, Y Takasu, Enhanced activity and stability of Pt/C fuel cell anodes by the modification with ruthenium-oxide nanosheets, Acta 55 (2010) 857–864 [406] H Zhu, S Zhang, Y Huang, L Wu, S Sun, Monodisperse MxFe3ÀxO4 (M=Fe, Cu, Co, Mn) nanoparticles and their electrocatalysis for oxygen reduction reaction, Nano Letters 13 (2013) 2947–2951 Nguyen Viet Long is the young International Scientist at Shanghai Institute of Ceramics, Chinese Academy of Sciences, China He received BSc degree of Physics in Solid State Physics at Department of Physics, Hanoi National University of Education, Hanoi, Vietnam He received M.Eng degree in Semiconductor, and Ph.D degree in Optical and Photonic materials at International Training Institute for Materials Science, Hanoi University of Science and Technology, Hanoi He was the Lecturer in General Physics Then, he worked as the Researcher in Department of Materials Science and Engineering, Nagoya Institute of Technology, Nagoya, Japan His research directions of platinum and palladium based catalysts are focused on fuel cells, and energy conversion with Professor Masayuki Nogami He worked as researcher or visiting Professor in Kyushu University, Fukuoka, Japan He became a member of Laboratory for Nanotechnology, Vietnam National University at Ho Chi Minh City Yong Yang is the Professor in Shanghai Institute of Ceramics, Chinese Academy of Sciences He received B.Eng and M Eng., Department of Materials Science and Engineering, Shanxi University of Science and Technology, China He also received Dr Eng., Shanghai Institute of Ceramics, Chinese Academy of Sciences, China He worked as JSPS postdoctoral research fellow and project Associate Professor in Department of Materials Science and Engineering, Nagoya Institute of Technology, Nagoya, Japan At present, he was officially appointed as Professor in Shanghai Institute of Ceramics, Chinese Academy of Sciences His main interested scientific areas of 676 research are focused on the preparation and self-assembly of metal nanomaterials, catalytic properties and optical properties such as Surface Plasmon Resonance (SPR) for potential applications SPR sensors, Surface-enhanced Raman spectroscopy (SERS), and nonlinear optical properties, surface modification of materials and optical film He was the author of more than 60 scientific publications in international peer-reviewed journals Masayuki Nogami was the Professor at Nagoya Institute of Technology (NIT), Nagoya, Japan He received B.S in Ceramics, then M.S in Ceramics at NIT, and Dr Eng at Osaka University He is Professor Emeritus at NIT, President of The Japanese Sol-Gel Society, Senior Researcher at Nagoya Industrial Science Research Institute, Senior Researcher at National Industrial Research Institute, Osaka, Visiting Research Associate at Rensselaer Polytechnic Institute, USA, and Associate Professor at Aichi Institute of Technology He has over 400 publications, 20 books, and 20 patents He was co-editor to Journal Sol-Gel Science and Technology (Springer-USA), Director Chairman of Glass Division in The Ceramics Society, Japan, Visiting Professor at National Engineering College for Industrial Ceramics, France He was Senior Researcher at Laboratory of Science of Ceramic Processes and of Surface Treatments, National Research Council (CNRs), French At present, he is the International Scientist at Shanghai Institute of Ceramics, Chinese Academy of Science, China Cao Minh Thi was the Professor of Mathematics and Physics, and Solid State Physics, in Ho Chi Minh University of Technology, 144/24 Dien Bien Phu, Ward 25, Binh Thanh, Ho Chi Minh City He received Bsc in Physics, Hanoi National University of Education (HNUE) Then, he studied in Mathematics and physics at Lomonosov Moscow State University, and received Ph.D in Mathematics and Physics at Lomonosov Moscow State University He was the Lecturer in Physics at HNUE, Vietnam, Lecturer of Faculty of Physics, HNUE He was appointed by Vietnamese Leaders of the Vietnam country as vice President of Ho Chi Minh City (HCMC) N.V Long et al University of Education or Saigon National Pedagogical University, President of Ho Chi Minh City University of Education (Saigon College), Associate professor, Deputy Director of Sector of Education and Training in the entire city At present, he is Vice-president of Vietnam Physical Society, President of HCMC Physical Society Nguyen Van Minh is the President of Hanoi National University of Education (HNUE), Hanoi At present, he is also the Associate Professor in HNUE He is the central member of the Vietnamese Physical Society, Hanoi, Vietnam In past, he received the Ph.D degree in Physics from HNUE, Hanoi, Vietnam Then, he became the lecturer in Physics at HNUE, and the Dean of the Department of Physics, HNUE He worked as the researcher, as the independent scientist with the use of Modern Raman techniques at Ewha Womans University, Seoul, Korea His interesting research is focused on the intensive investigations of nanosized materials by Raman methods He has over 30 papers in the fields of nanosized materials by Raman methods and other research fields Yanqin Cao is the Ph.D student at Shanghai Institute of Ceramics, Chinese Academy of Sciences She received B.Eng., Department of Materials Science and Engineering, Wuhan University of Science and Technology, China Her research is focused on the controlled synthesis of noble metal nanostructures, and Surface-enhanced Raman spectroscopy ... performance of the catalytic activity, the mixture of the The Development of Mixture, Alloy, and Core-Shell Nanocatalysts with Nanomaterial Supports for Energy Conversion nanoparticles and the supports. .. electrocatalytic behavior for The Development of Mixture, Alloy, and Core-Shell Nanocatalysts with Nanomaterial Supports for Energy Conversion DMFCs Interestingly, the size effects on the catalytic... occurs at the anode, and CO can heavily adsorb on a Pt-based catalyst and block the hydrogen The Development of Mixture, Alloy, and Core-Shell Nanocatalysts with Nanomaterial Supports for Energy Conversion