Core–Shell-Structured Low-Platinum Electrocatalysts for Fuel Cell Applications

Abstract

Pt-based catalysts are the most efficient catalysts for low-temperature fuel cells. However, commercialization is impeded by prohibitively high costs and scarcity. One of the most effective strategies to reduce Pt loading is to deposit a monolayer or a few layers of Pt over other metal cores to form core–shell-structured electrocatalysts. In core–shell-structured electrocatalysts, the compositions of the core can be divided into five classes: single-precious metallic cores represented by Pd, Ru, and Au; single-non-precious metallic cores represented by Cu, Ni, Co, and Fe; alloy cores containing 3d, 4d or 5d metals; and carbide and nitride cores. Of these, researchers have found that carbide and nitride cores can yield tremendous advantages over alloy cores in terms of cost and promotional activities of Pt shells. In addition, desirable shells with reasonable thicknesses and compositions have been recognized to play a dominant role in electrocatalytic performances. And recently, researchers have also found that the catalytic activity of core–shell-structured catalysts is dependent on the binding energy of the adsorbents, which is determined by the d-band center of Pt. The shifting of this d-band center in turn is mainly affected by strain and electronic effects, which can be adjusted by adjusting core compositions and shell thicknesses of catalysts. In the development of these core–shell structures, optimal synthesis methods are of primary concern because they directly determine the practical application potential of the resulting electrocatalysts. And in this article, the principles behind core–shell-structured low-Pt electrocatalysts and the developmental progresses of various synthesis methods along with the traits of each type of core and its effects on Pt shell catalytic activities are discussed. In addition, perspectives on this type of catalyst are discussed and future research directions are proposed.

Keywords

Core–shell structure / Shell formation / Shell thickness / Core composition / Core–shell interaction

References

[1] BP: Sustainability report. http://www.bp.com/content/dam/bp/pdf/sustainability/group-reports/bp-sustainability-report-2015.pdf (2015)

[2] U.S. Department of Energy: Fuel cell technologies office multi-year research, development, and demonstration plan. http://energy.gov/eere/fuelcells/downloads/fuel-cell-technologies-office-multi-year-research-development-and-22 (2018). Accessed 18 June 2018

[3] Kordesch KV, Simader GR Environmental impact of fuel cell technology. Chem. Rev., 1995, 95: 191-207.

[4] Wang H, Ma Y, Wang R, et al. Liquid–liquid interface-mediated room-temperature synthesis of amorphous NiCo pompoms from ultrathin nanosheets with high catalytic activity for hydrazine oxidation. Chem. Commun., 2015, 51: 3570-3573.

[5] Liu Y, Jiao Y, Yin B, et al. Enhanced electrochemical performance of hybrid SnO₂@MO _x (M = Ni, Co, Mn) core–shell nanostructures grown on flexible carbon fibers as the supercapacitor electrode matertials. J. Mater. Chem. A, 2015, 3: 3676-3682.

[6] Borup R, Meyers J, Pivovar B, et al. Scientific aspects of polymer electrolyte fuel cell durability and degradation. Chem. Rev., 2007, 107: 3904-3951.

[7] U.S. Department of Energy. Hydrogen & fuel cells program. https://www.hydrogen.energy.gov/program_records.html#fuel_cells (2018). Accessed 18 June 2018

[8] Saha MS, Neburchilov V, Ghosh D, et al. Nanomaterials-supported Pt catalysts for proton exchange membrane fuel cells. Wiley Interdiscip. Rev. Energy Environ., 2013, 2: 31-51.

[9] Gasteiger HA, Marković NM Just a dream—or future reality?. Science, 2009, 324: 48-49.

[10] Bing Y, Liu H, Zhang L, et al. Nanostructured Pt-alloy electrocatalysts for PEM fuel cell oxygen reduction reaction. Chem. Soc. Rev., 2010, 39: 2184-2202.

[11] Richards J “Precious” metals: the case for treating metals as irreplaceable. J. Clean. Prod., 2006, 14: 324-333.

[12] Mudd GM Key trends in the resource sustainability of platinum group elements. Ore Geol. Rev., 2012, 46: 106-117.

[13] LMC Automotive. http://www.lmc-auto.com/ (2018). Accessed 18 June 2018

[14] Besenbacher F, Chorkendorff II, Clausen BS, et al. Design of a surface alloy catalyst for steam reforming. Science, 1998, 279: 1913-1915.

[15] Greeley J, Mavrikakis M Alloy catalysts designed from first principles. Nat. Mater., 2004, 3: 810-815.

[16] Linic S, Jankowiak J, Barteau MA Selectivity driven design of bimetallic ethylene epoxidation catalysts from first principles. J. Catal., 2004, 224: 489-493.

[17] Greeley J, Jaramillo TF, Bonde J, et al. Computational high-throughput screening of electrocatalytic materials for hydrogen evolution. Nat. Mater., 2006, 5: 909-913.

[18] Wintterlin J, Völkening S, Janssens TVW, et al. Atomic and macroscopic reaction rates of a surface-catalyzed reaction. Science, 1997, 278: 1931-1934.

[19] Tao FF, Crozier PA Atomic-scale observations of catalyst structures under reaction conditions and during catalysis. Chem. Rev., 2016, 116: 3487-3539.

[20] Kabbabi A, Faure R, Durand R, et al. In situ FTIRS study of the electrocatalytic oxidation of carbon monoxide and methanol at platinum–ruthenium bulk alloy electrodes. J. Electroanal. Chem., 1998, 444: 41-53.

[21] Holstein WL, Rosenfeld HD In-situ X-ray absorption spectroscopy study of Pt and Ru chemistry during methanol electrooxidation. J. Phys. Chem. B, 2004, 109: 2176-2186.

[22] Stamenkovic VR, Mun BS, Arenz M, et al. Trends in electrocatalysis on extended and nanoscale Pt-bimetallic alloy surfaces. Nat. Mater., 2007, 6: 241-247.

[23] Cho J, Roh W, Kim DK, et al. X-Ray absorption spectroscopic and electrochemical analyses of Pt–Cu–Fe ternary alloy electrocatalysts supported on carbon. J. Chem. Soc., Faraday Trans., 1998, 94: 2835-2841.

[24] Yim WL, Klüner T Understanding of adsorption and catalytic properties of bimetallic Pt − Co alloy surfaces from first principles: insight from disordered alloy surfaces. J. Phys. Chem. C, 2010, 114: 7141-7152.

[25] Greco G, Witkowska A, Minicucci M, et al. Local ordering changes in Pt–Co nanocatalyst induced by fuel cell working conditions. J. Phys. Chem. C, 2012, 116: 12791-12802.

[26] Stephens IEL, Bondarenko AS, Gronbjerg U, et al. Understanding the electrocatalysis of oxygen reduction on platinum and its alloys. Energy Environ. Sci., 2012, 5: 6744-6762.

[27] Guo S, Zhang S, Sun S Tuning nanoparticle catalysis for the oxygen reduction reaction. Angew. Chem. Int. Ed., 2013, 52: 8526-8544.

[28] Qiao Y, Li CM Nanostructured catalysts in fuel cells. J. Mater. Chem., 2011, 21: 4027-4036.

[29] Morozan A, Jousselme B, Palacin S Low-platinum and platinum-free catalysts for the oxygen reduction reaction at fuel cell cathodes. Energy Environ. Sci., 2011, 4: 1238-1254.

[30] Inaba M, Daimon H Development of highly active and durable platinum core–shell catalysts for polymer electrolyte fuel cells. J. Jpn. Petrol. Inst., 2015, 58: 55-63.

[31] Liu HL, Nosheen F, Wang X Noble metal alloy complex nanostructures: controllable synthesis and their electrochemical property. Chem. Soc. Rev., 2015, 44: 3056-3078.

[32] Yang H Platinum-based electrocatalysts with core–shell nanostructures. Angew. Chem. Int. Ed., 2011, 50: 2674-2676.

[33] Oezaslan M, Hasché F, Strasser P Pt-based core–shell catalyst architectures for oxygen fuel cell electrodes. J. Phys. Chem. Lett., 2013, 4: 3273-3291.

[34] Liao H, Fisher A, Xu ZJ Surface segregation in bimetallic nanoparticles: a critical issue in electrocatalyst engineering. Small, 2015, 11: 3221-3246.

[35] Adzic RR, Zhang J, Sasaki K, et al. Platinum monolayer fuel cell electrocatalysts. Top. Catal., 2007, 46: 249-262.

[36] Shao M, Chang Q, Dodelet JP, et al. Recent advances in electrocatalysts for oxygen reduction reaction. Chem. Rev., 2016, 116: 3594-3657.

[37] Wang X, Vara M, Luo M, et al. Pd@Pt core–shell concave decahedra: a class of catalysts for the oxygen reduction reaction with enhanced activity and durability. J. Am. Chem. Soc., 2015, 137: 15036-15042.

[38] Pelizzetti E Fine Particles Science and Technology—From Micro to Nanoparticles 1996 Dordrecht Kluwer Academic Publishers

[39] Nguyen VL, Ohtaki M, Matsubara T, et al. 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, 2012, 116: 12265-12274.

[40] Li Y, Wang ZW, Chiu CY, et al. Synthesis of bimetallic Pt–Pd core–shell nanocrystals and their high electrocatalytic activity modulated by Pd shell thickness. Nanoscale, 2012, 4: 845-851.

[41] Habas SE, Lee H, Radmilovic V, et al. Shaping binary metal nanocrystals through epitaxial seeded growth. Nat. Mater., 2007, 6: 692-697.

[42] Zhang GR, Wu J, Xu B-Q Syntheses of sub-30 nm Au@Pd concave nanocubes and Pt-on-(Au@Pd) trimetallic nanostructures as highly efficient catalysts for ethanol oxidation. J. Phys. Chem. C, 2012, 116: 20839-20847.

[43] Guo S, Zhang X, Zhu W, et al. Nanocatalyst superior to Pt for oxygen reduction reactions: the case of core/shell Ag(Au)/CuPd nanoparticles. J. Am. Chem. Soc., 2014, 136: 15026-15033.

[44] Gu J, Guo Y, Jiang YY, et al. Robust phase control through hetero-seeded epitaxial growth for face-centered cubic Pt@Ru nanotetrahedrons with superior hydrogen electro-oxidation activity. J. Phys. Chem. C, 2015, 119: 17697-17706.

[45] Choi R, Choi SI, Choi CH, et al. Designed synthesis of well-defined Pd@Pt core–shell nanoparticles with controlled shell thickness as efficient oxygen reduction electrocatalysts. Chem. Eur. J., 2013, 19: 8190-8198.

[46] Lim B, Jiang M, Camargo PH, et al. Pd–Pt bimetallic nanodendrites with high activity for oxygen reduction. Science, 2009, 324: 1302-1305.

[47] Li J, Zhou P, Li F, et al. Ni@Pd/PEI–rGO stack structures with controllable Pd shell thickness as advanced electrodes for efficient hydrogen evolution. J. Mater. Chem. A, 2015, 3: 11261-11268.

[48] Mazumder V, Chi M, More KL, et al. Synthesis and characterization of multimetallic Pd/Au and Pd/Au/FePt core/shell nanoparticles. Angew. Chem. Int. Ed., 2010, 49: 9368-9372.

[49] Jauhar AM, Hassan FM, Cano ZP, et al. Platinum–palladium core–shell nanoflower catalyst with improved activity and excellent durability for the oxygen reduction reaction. Adv. Mater. Interfaces, 2018, 5: 1701508.

[50] Bao S, Vara M, Yang X, et al. Facile synthesis of Pd@Pt_3–L core–shell octahedra with a clean surface and thus enhanced activity toward oxygen reduction. ChemCatChem, 2017, 9: 414-419.

[51] Lim B, Wang J, Camargo PH, et al. Facile synthesis of bimetallic nanoplates consisting of Pd cores and Pt shells through seeded epitaxial growth. Nano Lett., 2008, 8: 2535-2540.

[52] Wang Y, Toshima N Preparation of Pd–Pt bimetallic colloids with controllable core/shell structures. J. Phys. Chem. B, 1997, 101: 5301-5306.

[53] Xu S, Li Z, Lei F, et al. Facile synthesis of hydrangea-like core–shell Pd@Pt/graphene composite as an efficient electrocatalyst for methanol oxidation. Appl. Surf. Sci., 2017, 426: 351-359.

[54] Hong JW, Kang SW, Choi BS, et al. Controlled synthesis of Pd–Pt alloy hollow nanostructures with enhanced catalytic activities for oxygen reduction. ACS Nano, 2012, 6: 2410-2419.

[55] Peng Z, Yang H Synthesis and oxygen reduction electrocatalytic property of Pt-on-Pd bimetallic heteronanostructures. J. Am. Chem. Soc., 2009, 131: 7542-7543.

[56] Miyakawa M, Hiyoshi N, Nishioka M, et al. Continuous syntheses of Pd@Pt and Cu@Ag core–shell nanoparticles using microwave-assisted core particle formation coupled with galvanic metal displacement. Nanoscale, 2014, 6: 8720-8725.

[57] Yang CC, Chen HR, Lee CL Sub 10-nm Pd nanocubes and their coating with multi-armed Pt shells: facile synthesis and catalysis of alkaline oxygen reduction. J. Electrochem. Soc., 2015, 162: H512-H517.

[58] Qi K, Zheng W, Cui X Supersaturation-controlled surface structure evolution of Pd@Pt core–shell nanocrystals: enhancement of the ORR activity at a sub-10 nm scale. Nanoscale, 2016, 8: 1698-1703.

[59] De Clercq A, Margeat O, Sitja G, et al. Core–shell Pd–Pt nanocubes for the CO oxidation. J. Catal., 2016, 336: 33-40.

[60] Lee YW, Lee JY, Kwak DH, et al. Pd@Pt core–shell nanostructures for improved electrocatalytic activity in methanol oxidation reaction. Appl. Catal. B, 2015, 179: 178-184.

[61] Ren F, Lu H, Liu H, et al. Surface ligand-mediated isolated growth of Pt on Pd nanocubes for enhanced hydrogen evolution activity. J. Mater. Chem. A, 2015, 3: 23660-23663.

[62] Xie S, Choi SI, Lu N, et al. Atomic layer-by-layer deposition of Pt on Pd nanocubes for catalysts with enhanced activity and durability toward oxygen reduction. Nano Lett., 2014, 14: 3570-3576.

[63] Park J, Zhang L, Choi SI, et al. Atomic layer-by-layer deposition of platinum on palladium octahedra for enhanced catalysts toward the oxygen reduction reaction. ACS Nano, 2015, 9: 2635-2647.

[64] Wongkaew A, Zhang Y, Tengco JMM, et al. Characterization and evaluation of Pt–Pd electrocatalysts prepared by electroless deposition. Appl. Catal. B, 2016, 188: 367-375.

[65] Zhang H, Yin Y, Hu Y, et al. Pd@Pt core − shell nanostructures with controllable composition synthesized by a microwave method and their enhanced electrocatalytic activity toward oxygen reduction and methanol oxidation. J. Phys. Chem. C, 2010, 114: 11861-11867.

[66] Zhao R, Liu Y, Liu C, et al. Pd@ Pt core–shell tetrapods as highly active and stable electrocatalysts for the oxygen reduction reaction. J. Mater. Chem. A, 2014, 2: 20855-20860.

[67] Kim Y, Noh Y, Lim EJ, et al. Star-shaped Pd@Pt core–shell catalysts supported on reduced graphene oxide with superior electrocatalytic performance. J. Mater. Chem. A, 2014, 2: 6976.

[68] Chen Y, Yang J, Yang Y, et al. A facile strategy to synthesize three-dimensional Pd@ Pt core–shell nanoflowers supported on graphene nanosheets as enhanced nanoelectrocatalysts for methanol oxidation. Chem. Commun., 2015, 51: 10490-10493.

[69] Choi SI, Shao M, Lu N, et al. Synthesis and characterization of Pd@ Pt–Ni core–shell octahedra with high activity toward oxygen reduction. ACS Nano, 2014, 8: 10363-10371.

[70] Zhao X, Chen S, Fang Z, et al. Octahedral Pd@Pt1.8Ni core–shell nanocrystals with ultrathin PtNi alloy shells as active catalysts for oxygen reduction reaction. J. Am. Chem. Soc., 2015, 137: 2804-2807.

[71] Bai S, Wang C, Deng M, et al. Surface polarization matters: enhancing the hydrogen-evolution reaction by shrinking Pt shells in Pt–Pd-graphene stack structures. Angew. Chem. Int. Ed., 2014, 53: 12120-12124.

[72] Zhang H, Jin M, Wang J, et al. Nanocrystals composed of alternating shells of Pd and Pt can be obtained by sequentially adding different precursors. J. Am. Chem. Soc., 2011, 133: 10422-10425.

[73] Liu L, Samjeske G, Nagamatsu SI, et al. 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, 2012, 116: 23453-23464.

[74] Lee SY, Jung N, Shin DY, et al. Self-healing Pd₃Au@Pt/C core–shell electrocatalysts with substantially enhanced activity and durability towards oxygen reduction. Appl. Catal. B, 2017, 206: 666-674.

[75] Mazumder V, Chi M, More KL, et al. Core/shell Pd/FePt nanoparticles as an active and durable catalyst for the oxygen reduction reaction. J. Am. Chem. Soc., 2010, 132: 7848-7849.

[76] Aricò AS, Stassi A, D’Urso C, et al. Synthesis of Pd₃Co₁@Pt/C core–shell catalysts for methanol-tolerant cathodes of direct methanol fuel cells. Chem. Eur. J., 2014, 20: 10679-10684.

[77] Hwang SJ, Yoo SJ, Shin J, et al. Supported core@shell electrocatalysts for fuel cells: close encounter with reality. Sci. Rep., 2013, 3: 1309.

[78] Yang J, Yang J, Ying JY Morphology and lateral strain control of Pt nanoparticles via core–shell construction using alloy AgPd core toward oxygen reduction reaction. ACS Nano, 2012, 6: 9373-9382.

[79] Kang Y, Qi L, Li M, et al. Highly active Pt₃Pb and core–shell Pt₃Pb–Pt electrocatalysts for formic acid oxidation. ACS Nano, 2012, 6: 2818-2825.

[80] Somodi F, Werner S, Peng Z, et al. Size and composition control of Pt–In nanoparticles prepared by seed-mediated growth using bimetallic seeds. Langmuir ACS J. Surf. Colloids, 2012, 28: 3345-3349.

[81] Kim Y, Hong JW, Lee YW, et al. Synthesis of AuPt heteronanostructures with enhanced electrocatalytic activity toward oxygen reduction. Angew. Chem. Int. Ed., 2010, 49: 10197-10201.

[82] Banerjee I, Kumaran V, Santhanam V Synthesis and characterization of Au@Pt nanoparticles with ultrathin platinum overlayers. J. Phys. Chem. C, 2015, 119: 5982-5987.

[83] Thongthai K, Srisombat L, Saipanya S, et al. Morphology and catalytic activity of gold core-platinum shell nanoparticles. Chiang Mai J. Sci., 2015, 42: 481-489.

[84] Chen L, Kuai L, Geng B Shell structure-enhanced electrocatalytic performance of Au–Pt core–shell catalyst. CrystEngComm, 2013, 15: 2133.

[85] Srivastava SK, del Río JS, O’Sullivan CK, et al. Electro-catalytically active Au@ Pt nanoparticles for hydrogen evolution reaction: an insight into a tryptophan mediated supramolecular interface towards a universal core–shell synthesis approach. RSC Adv., 2014, 4: 48458-48464.

[86] Zhang Y, Li X, Li K, et al. Novel Au catalysis strategy for the synthesis of Au@Pt core–shell nanoelectrocatalyst with self-controlled quasi-monolayer Pt skin. ACS Appl. Mater. Interfaces., 2017, 9: 32688-32697.

[87] Liu R, Liu JF, Zhang ZM, et al. Submonolayer-Pt-coated ultrathin Au nanowires and their self-organized nanoporous film: SERS and catalysis active substrates for operando SERS monitoring of catalytic reactions. J. Phys. Chem. Lett., 2014, 5: 969-975.

[88] Yuan W, Fan X, Cui ZM, et al. Controllably self-assembled graphene-supported Au@Pt bimetallic nanodendrites as superior electrocatalysts for methanol oxidation in direct methanol fuel cells. J. Mater. Chem. A, 2016, 4: 7352-7364.

[89] Li Y, Ding W, Li M, et al. Synthesis of core–shell Au–Pt nanodendrites with high catalytic performance via overgrowth of platinum on in situ gold nanoparticles. J. Mater. Chem. A, 2015, 3: 368-376.

[90] Sarkar A, Kerr JB, Cairns EJ Electrochemical oxygen reduction behavior of selectively deposited platinum atoms on gold nanoparticles. ChemPhysChem, 2013, 14: 2132-2142.

[91] Shen LL, Zhang GR, Miao S, et al. Core–shell nanostructured Au@Ni _mPt₂ electrocatalysts with enhanced activity and durability for oxygen reduction reaction. ACS Catal., 2016, 6: 1680-1690.

[92] Chen TY, Lin TL, Luo TJM, et al. Effects of Pt shell thicknesses on the atomic structure of Ru–Pt core–shell nanoparticles for methanol electrooxidation applications. ChemPhysChem, 2010, 11: 2383-2392.

[93] Chen TY, Chen IL, Liu YT, et al. Core-dependent growth of platinum shell nanocrystals and their electrochemical characteristics for fuel cells. CrystEngComm, 2013, 15: 982-994.

[94] Hsieh YC, Zhang Y, Su D, et al. Ordered bilayer ruthenium-platinum core–shell nanoparticles as carbon monoxide-tolerant fuel cell catalysts. Nat. Commun., 2013, 4: 2466.

[95] Goto S, Hosoi S, Arai R, et al. Particle-size- and Ru-core-induced surface electronic states of Ru-core/Pt-shell electrocatalyst nanoparticles. J. Phys. Chem. C, 2014, 118: 2634-2640.

[96] Zhao ZL, Zhang LY, Bao SJ, et al. One-pot synthesis of small and uniform Au@PtCu core–alloy shell nanoparticles as an efficient electrocatalyst for direct methanol fuel cells. Appl. Catal. B, 2015, 174–175: 361-366.

[97] Su S, Zhang C, Yuwen L, et al. Uniform Au@Pt core–shell nanodendrites supported on molybdenum disulfide nanosheets for the methanol oxidation reaction. Nanoscale, 2016, 8: 602-608.

[98] Peng Z, Wu J, Yang H Synthesis and oxygen reduction electrocatalytic property of platinum hollow and platinum-on-silver nanoparticles. Chem. Mater., 2009, 22: 1098-1106.

[99] Gowthaman N, John SA Modification of a glassy carbon electrode with gold–platinum core–shell nanoparticles by electroless deposition and their electrocatalytic activity. RSC Adv., 2015, 5: 42369-42375.

[100] Rashid M, Jun TS, Jung Y, et al. Bimetallic core–shell Ag@Pt nanoparticle-decorated MWNT electrodes for amperometric H₂ sensors and direct methanol fuel cells. Sens. Actuators B Chem., 2015, 208: 7-13.

[101] Khi NT, Yoon J, Kim H, et al. Axially twinned nanodumbbell with a Pt bar and two Rh@Pt balls designed for high catalytic activity. Nanoscale, 2013, 5: 5738-5742.

[102] Zhang H, Jin M, Liu H, et al. Facile synthesis of Pd–Pt alloy nanocages and their enhanced performance for preferential oxidation of CO in excess hydrogen. ACS Nano, 2011, 5: 8212-8222.

[103] Li C, Yamauchi Y Facile solution synthesis of Ag@Pt core–shell nanoparticles with dendritic Pt shells. Phys. Chem. Chem. Phys., 2013, 15: 3490-3496.

[104] Fu T, Fang J, Wang C, et al. Hollow porous nanoparticles with Pt skin on a Ag–Pt alloy structure as a highly active electrocatalyst for the oxygen reduction reaction. J. Mater. Chem. A, 2016, 4: 8803-8811.

[105] Cao J, Guo M, Wu J, et al. Carbon-supported Ag@Pt core–shell nanoparticles with enhanced electrochemical activity for methanol oxidation and oxygen reduction reaction. J. Power Sources, 2015, 277: 155-160.

[106] Pech-Pech IE, Gervasio DF, Godínez-Garcia A, et al. Nanoparticles of Ag with a Pt and Pd rich surface supported on carbon as a new catalyst for the oxygen electroreduction reaction (ORR) in acid electrolytes: part 1. J. Power Sources, 2015, 276: 365-373.

[107] Wu D, Cheng D Core/shell AgNi/PtAgNi nanoparticles as methanol-tolerant oxygen reduction electrocatalysts. Electrochim. Acta, 2015, 180: 316-322.

[108] Xie J, Zhang Q, Gu L, et al. Ruthenium–platinum core–shell nanocatalysts with substantially enhanced activity and durability towards methanol oxidation. Nano Energy, 2016, 21: 247-257.

[109] Elbert K, Hu J, Ma Z, et al. Elucidating hydrogen oxidation/evolution kinetics in base and acid by enhanced activities at the optimized Pt shell thickness on the Ru core. ACS Catal., 2015, 5: 6764-6772.

[110] Zhou S, McIlwrath K, Jackson G, et al. Enhanced CO tolerance for hydrogen activation in Au–Pt dendritic heteroaggregate nanostructures. J. Am. Chem. Soc., 2006, 128: 1780-1781.

[111] Alayoglu S, Nilekar AU, Mavrikakis M, et al. Ru–Pt core–shell nanoparticles for preferential oxidation of carbon monoxide in hydrogen. Nat. Mater., 2008, 7: 333-338.

[112] Pupo MMS, López-Suárez FE, Bueno-López A, et al. Sn@Pt and Rh@Pt core–shell nanoparticles synthesis for glycerol oxidation. J. Appl. Electrochem., 2014, 45: 139-150.

[113] Gao H, Liao S, Zeng J, et al. Platinum decorated Ru/C: effects of decorated platinum on catalyst structure and performance for the methanol oxidation reaction. J. Power Sources, 2011, 196: 54-61.

[114] Ryu J, Choi J, Lim DH, et al. Morphology-controlled synthesis of ternary Pt–Pd–Cu alloy nanoparticles for efficient electrocatalytic oxygen reduction reactions. Appl. Catal. B, 2015, 174–175: 526-532.

[115] Cochell T, Li W, Manthiram A Effects of Pt coverage in Pt@PdCu₅/C core–shell electrocatalysts on the oxygen reduction reaction and methanol tolerance. J. Phys. Chem. C, 2013, 117: 3865-3873.

[116] Li H, Wu H, Zhai Y, et al. Synthesis of monodisperse plasmonic Au core–Pt shell concave nanocubes with superior catalytic and electrocatalytic activity. ACS Catal., 2013, 3: 2045-2051.

[117] Dai Y, Chen S Oxygen reduction electrocatalyst of Pt on Au nanoparticles through spontaneous deposition. ACS Appl. Mater. Interfaces., 2015, 7: 823-829.

[118] Kuai L, Geng B, Wang S, et al. A general and high-yield galvanic displacement approach to Au–M (M = Au, Pd, and Pt) core–shell nanostructures with porous shells and enhanced electrocatalytic performances. Chem. Eur. J., 2012, 18: 9423-9429.

[119] Liu X, Xu G, Chen Y, et al. A strategy for fabricating porous PdNi@Pt core–shell nanostructures and their enhanced activity and durability for the methanol electrooxidation. Sci. Rep., 2015, 5: 7619.

[120] Ye F, Liu H, Hu W, et al. Heterogeneous Au–Pt nanostructures with enhanced catalytic activity toward oxygen reduction. Dalton Trans., 2012, 41: 2898-2903.

[121] Wang G, Huang B, Xiao L, et al. Pt skin on AuCu intermetallic substrate: a strategy to maximize Pt utilization for fuel cells. J. Am. Chem. Soc., 2014, 136: 9643-9649.

[122] Liu J, Zhang M, Liu J, et al. Synthesis of Ag@ Pt core–shell nanoparticles loaded onto reduced graphene oxide and investigation of its electrosensing properties. Anal. Methods, 2016, 8: 1084-1090.

[123] Li HH, Cui CH, Zhao S, et al. Mixed-PtPd-shell PtPdCu nanoparticle nanotubes templated from copper nanowires as efficient and highly durable electrocatalysts. Adv. Energy Mater., 2012, 2: 1182-1187.

[124] Sarkar A, Manthiram A Synthesis of Pt@Cu core − shell nanoparticles by galvanic displacement of Cu by Pt⁴⁺ ions and their application as electrocatalysts for oxygen reduction reaction in fuel cells. J. Phys. Chem. C, 2010, 114: 4725-4732.

[125] Sun Z, Masa J, Xia W, et al. Rapid and surfactant-free synthesis of bimetallic Pt–Cu nanoparticles simply via ultrasound-assisted redox replacement. ACS Catal., 2012, 2: 1647-1653.

[126] Jeon TY, Pinna N, Yoo SJ, et al. Selective deposition of Pt onto supported metal clusters for fuel cell electrocatalysts. Nanoscale, 2012, 4: 6461-6469.

[127] Yang J, Zhou W, Cheng CH, et al. Pt-decorated PdFe nanoparticles as methanol-tolerant oxygen reduction electrocatalyst. ACS Appl. Mater. Interfaces., 2010, 2: 119-126.

[128] Cochell T, Manthiram A Pt@Pd _xCu _y/C core–shell electrocatalysts for oxygen reduction reaction in fuel cells. Langmuir ACS J. Surf. Colloids, 2012, 28: 1579-1587.

[129] Yang J, Lee JY, Chen L, et al. A phase-transfer identification of core–shell structures in Ag–Pt nanoparticles. J. Phys. Chem. B, 2005, 109: 5468-5472.

[130] Zhang W, Yang J, Lu X Tailoring galvanic replacement reaction for the preparation of Pt/Ag bimetallic hollow nanostructures with controlled number of voids. ACS Nano, 2012, 6: 7397-7405.

[131] Zeng J, Yang J, Lee JY, et al. Preparation of carbon-supported core–shell Au–Pt nanoparticles for methanol oxidation reaction: the promotional effect of the Au core. J. Phys. Chem. B, 2006, 110: 24606-24611.

[132] Brankovic SR, Wang JX, Adžić RR Pt submonolayers on Ru nanoparticles: a novel low Pt loading, high CO tolerance fuel cell electrocatalyst. Electrochem. Solid-State Lett., 2001, 4: A217.

[133] Jeena SE, Selvaraju T Facile growth of Ag@Pt bimetallic nanorods on electrochemically reduced graphene oxide for an enhanced electrooxidation of hydrazine. J. Chem. Sci., 2016, 128: 357-363.

[134] Lim T, Kim OH, Sung YE, et al. Preparation of onion-like Pt-terminated Pt–Cu bimetallic nano-sized electrocatalysts for oxygen reduction reaction in fuel cells. J. Power Sources, 2016, 316: 124-131.

[135] Wang W, Wang R, Ji S, et al. Pt overgrowth on carbon supported PdFe seeds in the preparation of core–shell electrocatalysts for the oxygen reduction reaction. J. Power Sources, 2010, 195: 3498-3503.

[136] Petrii OA Electrosynthesis of nanostructures and nanomaterials. Russ. Chem. Rev., 2015, 84: 159.

[137] Zhang W, Wang R, Wang H, et al. High performance carbon-supported core@Shell PdSn@Pt electrocatalysts for oxygen reduction reaction. Fuel Cells, 2010, 10: 734-739.

[138] Ataee-Esfahani H, Wang L, Nemoto Y, et al. Synthesis of bimetallic Au@ Pt nanoparticles with Au core and nanostructured Pt shell toward highly active electrocatalysts. Chem. Mater., 2010, 22: 6310-6318.

[139] Chen LX, Liu L, Feng JJ, et al. Oligonucleotide-assisted successive coreduction synthesis of dendritic platinum–gold core–shell alloy nanocrystals with improved electrocatalytic performance for methanol oxidation. J. Power Sources, 2016, 302: 140-145.

[140] Kim Y, Lee YW, Kim M, et al. One-pot synthesis and electrocatalytic properties of Pd@Pt core–shell nanocrystals with tailored morphologies. Chemistry, 2014, 20: 7901-7905.

[141] Jiang B, Li C, Henzie J, et al. Morphosynthesis of nanoporous pseudo Pd@Pt bimetallic particles with controlled electrocatalytic activity. J. Mater. Chem. A, 2016, 4: 6465-6471.

[142] Wang Q, Li Y, Liu B, et al. A facile reflux procedure to increase active surface sites form highly active and durable supported palladium@platinum bimetallic nanodendrites. J. Power Sources, 2015, 297: 59-67.

[143] Wang L, Nemoto Y, Yamauchi Y Direct synthesis of spatially-controlled Pt-on-Pd bimetallic nanodendrites with superior electrocatalytic activity. J. Am. Chem. Soc., 2011, 133: 9674-9677.

[144] Ataee-Esfahani H, Imura M, Yamauchi Y All-metal mesoporous nanocolloids: solution-phase synthesis of core–shell Pd@Pt nanoparticles with a designed concave surface. Angew. Chem. Int. Ed., 2013, 52: 13611-13615.

[145] Zhang Y, Bu L, Jiang K, et al. Concave PdPt core–shell nanocrystals with ultrathin Pt shell feature and enhanced catalytic performance. Small, 2016, 12: 706-712.

[146] Liu Q, Xu YR, Wang AJ, et al. A single-step route for large-scale synthesis of core–shell palladium@platinum dendritic nanocrystals/reduced graphene oxide with enhanced electrocatalytic properties. J. Power Sources, 2016, 302: 394-401.

[147] Lim Y, Kim SK, Lee SC, et al. One-step synthesis of carbon-supported Pd@Pt/C core–shell nanoparticles as oxygen reduction electrocatalysts and their enhanced activity and stability. Nanoscale, 2014, 6: 4038-4042.

[148] Yoon J, Kang S, Baik H, et al. One-pot synthesis of a highly active, non-spherical PdPt@Pt core–shell nanospike electrocatalyst exhibiting a thin Pt shell with multiple grain boundaries. RSC Adv., 2014, 4: 46521-46526.

[149] Zhang N, Guo S, Zhu X, et al. Hierarchical Pt/Pt _xPb core/shell nanowires as efficient catalysts for electrooxidation of liquid fuels. Chem. Mater., 2016, 28: 4447-4452.

[150] Li SS, Lv JJ, Teng LN, et al. Facile synthesis of PdPt@Pt nanorings supported on reduced graphene oxide with enhanced electrocatalytic properties. ACS Appl. Mater. Interfaces., 2014, 6: 10549-10555.

[151] Liu L, Lin XX, Zou SY, et al. One-pot wet-chemical synthesis of PtPd@Pt nanocrystals supported on reduced graphene oxide with highly electrocatalytic performance for ethylene glycol oxidation. Electrochim. Acta, 2016, 187: 576-583.

[152] Zhu J, Xiao M, Li K, et al. Superior electrocatalytic activity from nanodendritic structure consisting of a PtFe bimetallic core and Pt shell. Chem. Commun., 2015, 51: 3215-3218.

[153] Matin MA, Lee E, Kim H, et al. Rational syntheses of core–shell Fe@(PtRu) nanoparticle electrocatalysts for the methanol oxidation reaction with complete suppression of CO-poisoning and highly enhanced activity. J. Mater. Chem. A, 2015, 3: 17154-17164.

[154] Hwang ET, Lee YW, Park HC, et al. Synthesis of Pt-Rich@ Pt–Ni alloy core–shell nanoparticles using halides. RSC Adv., 2015, 5: 8301-8306.

[155] Wu ML, Chen DH, Huang TC Preparation of Au/Pt bimetallic nanoparticles in water-in-oil microemulsions. Chem. Mater., 2001, 13: 599-606.

[156] Garcia-Gutierrez DI, Gutierrez-Wing CE, Giovanetti L, et al. Temperature effect on the synthesis of Au–Pt bimetallic nanoparticles. J. Phys. Chem. B, 2005, 109: 3813-3821.

[157] Bian T, Zhang H, Jiang Y, et al. Epitaxial growth of twinned Au–Pt core–shell star-shaped decahedra as highly durable electrocatalysts. Nano Lett., 2015, 15: 7808-7815.

[158] Xu Z, Carlton CE, Allard LF, et al. Direct colloidal route for Pt-covered AuPt bimetallic nanoparticles. J. Phys. Chem. Lett., 2010, 1: 2514-2518.

[159] Shi Q, Zhu C, Fu S, et al. One-pot fabrication of mesoporous core–shell Au@PtNi ternary metallic nanoparticles and their enhanced efficiency for oxygen reduction reaction. ACS Appl. Mater. Interfaces., 2016, 8: 4739-4744.

[160] Xia T, Liu J, Wang S, et al. Enhanced catalytic activities of NiPt truncated octahedral nanoparticles toward ethylene glycol oxidation and oxygen reduction in alkaline electrolyte. ACS Appl. Mater. Interfaces., 2016, 8: 10841-10849.

[161] Zhang Y, Han T, Fang J, et al. Integrated Pt₂Ni alloy@Pt core–shell nanoarchitectures with high electrocatalytic activity for oxygen reduction reaction. J. Mater. Chem. A, 2014, 2: 11400-11407.

[162] Jang JH, Kim J, Lee YH, et al. One-pot synthesis of core–shell-like Pt₃Co nanoparticle electrocatalyst with Pt-enriched surface for oxygen reduction reaction in fuel cells. Energy Environ. Sci., 2011, 4: 4947-4953.

[163] Wang L, Yamauchi Y Autoprogrammed synthesis of triple-layered Au@Pd@Pt core − shell nanoparticles consisting of a Au@Pd bimetallic core and nanoporous Pt shell. J. Am. Chem. Soc., 2010, 132: 13636-13638.

[164] Wang L, Yamauchi Y Strategic synthesis of trimetallic Au@Pd@Pt core − shell nanoparticles from poly (vinylpyrrolidone)-based aqueous solution toward highly active electrocatalysts. Chem. Mater., 2011, 23: 2457-2465.

[165] Yuan Q, Huang DB, Wang HH, et al. One-pot synthesis of Pd–Pt@Pd core–shell nanocrystals with enhanced electrocatalytic activity for formic acid oxidation. CrystEngComm, 2014, 16: 2560.

[166] Zhang G, Liu Z, Xiao Z, et al. Ni₂P-graphite nanoplatelets supported Au–Pd core–shell nanoparticles with superior electrochemical properties. J. Phys. Chem. C, 2015, 119: 10469-10477.

[167] Datta KJ, Datta KKR, Gawande MB, et al. Pd@Pt core–shell nanoparticles with branched dandelion-like morphology as highly efficient catalysts for olefin reduction. Chem. Eur. J., 2016, 22: 1577-1581.

[168] Tojo C, Buceta D, López-Quintela MA Understanding the metal distribution in core–shell nanoparticles prepared in micellar media. Nanoscale Res. Lett., 2015, 10: 339.

[169] Yuan Q, Zhou Z, Zhuang J, et al. Pd–Pt random alloy nanocubes with tunable compositions and their enhanced electrocatalytic activities. Chem. Commun., 2010, 46: 1491-1493.

[170] Xu D, Liu Z, Yang H, et al. Solution-based evolution and enhanced methanol oxidation activity of monodisperse platinum–copper nanocubes. Angew. Chem. Int. Ed., 2009, 48: 4217-4221.

[171] Huang X, Zhang H, Guo C, et al. Simplifying the creation of hollow metallic nanostructures: one-pot synthesis of hollow palladium/platinum single-crystalline nanocubes. Angew. Chem. Int. Ed., 2009, 121: 4902-4906.

[172] Tojo C, de Dios M, Buceta D, et al. Cage-like effect in Au–Pt nanoparticle synthesis in microemulsions: a simulation study. Phys. Chem. Chem. Phys., 2014, 16: 19720-19731.

[173] Lai S, Fu C, Chen Y, et al. Pt-content-controlled synthesis of Pd nanohollows/Pt nanorods core/shell composites with enhanced electrocatalytic activities for the methanol oxidation reaction. J. Power Sources, 2015, 274: 604-610.

[174] Li HH, Ma SY, Fu QQ, et al. Scalable bromide-triggered synthesis of Pd@Pt core–shell ultrathin nanowires with enhanced electrocatalytic performance toward oxygen reduction reaction. J. Am. Chem. Soc., 2015, 137: 7862-7868.

[175] Hong W, Wang J, Wang E Dendritic Au/Pt and Au/PtCu nanowires with enhanced electrocatalytic activity for methanol electrooxidation. Small, 2014, 10: 3262-3265.

[176] Hu Y, Zhu A, Zhang Q, et al. Fabrication of hollow platinum–ruthenium core–shell catalysts with nanochannels and enhanced performance for methanol oxidation. J. Power Sources, 2015, 299: 443-450.

[177] Crabb E, Ravikumar M, Thompsett D, et al. Effect of Ru surface composition on the CO tolerance of Ru modified carbon supported Pt catalysts. Phys. Chem. Chem. Phys., 2004, 6: 1792-1798.

[178] Wells PP, Crabb EM, King CR, et al. Preparation, structure, and stability of Pt and Pd monolayer modified Pd and Pt electrocatalysts. Phys. Chem. Chem. Phys., 2009, 11: 5773-5781.

[179] Deogratias N, Ji M, Zhang Y, et al. Core@shell sub-ten-nanometer noble metal nanoparticles with a controllable thin Pt shell and their catalytic activity towards oxygen reduction. Nano Res., 2014, 8: 271-280.

[180] Xu C, Liu Y, Wang J, et al. Fabrication of nanoporous Cu–Pt (Pd) core/shell structure by galvanic replacement and its application in electrocatalysis. ACS Appl. Mater. Interfaces., 2011, 3: 4626-4632.

[181] Xie W, Herrmann C, Kömpe K, et al. Synthesis of bifunctional Au/Pt/Au core/shell nanoraspberries for in situ SERS monitoring of platinum-catalyzed reactions. J. Am. Chem. Soc., 2011, 133: 19302-19305.

[182] Cui C, Gan L, Li HH, et al. Octahedral PtNi nanoparticle catalysts: exceptional oxygen reduction activity by tuning the alloy particle surface composition. Nano Lett., 2012, 12: 5885-5889.

[183] Zhu H, Zhang S, Su D, et al. Surface profile control of FeNiPt/Pt core/shell nanowires for oxygen reduction reaction. Small, 2015, 11: 3545-3549.

[184] Wang R, Ma Y, Wang H, et al. Gas-liquid interface-mediated room-temperature synthesis of “clean” PdNiP alloy nanoparticle networks with high catalytic activity for ethanol oxidation. Chem. Commun., 2014, 50: 12877-12879.

[185] Ma Y, Wang R, Wang H, et al. Room-temperature synthesis with inert bubble templates to produce “clean” PdCoP alloy nanoparticle networks for enhanced hydrazine electro-oxidation. RSC Adv., 2015, 5: 9837-9842.

[186] Chen X, Wu G, Chen J, et al. Synthesis of “clean” and well-dispersive Pd nanoparticles with excellent electrocatalytic property on graphene oxide. J. Am. Chem. Soc., 2011, 133: 3693-3695.

[187] Wanjala BN, Fang B, Shan S, et al. Design of ternary nanoalloy catalysts: effect of nanoscale alloying and structural perfection on electrocatalytic enhancement. Chem. Mater., 2012, 24: 4283-4293.

[188] Choi SI, Xie S, Shao M, et al. Synthesis and characterization of 9 nm Pt–Ni octahedra with a record high activity of 3.3 A/mg_Pt for the oxygen reduction reaction. Nano Lett., 2013, 13: 3420-3425.

[189] Zhang XT, Wang H, Key JL, et al. Strain effect of core–shell Co@Pt/C nanoparticle catalyst with enhanced electrocatalytic activity for methanol oxidation. J. Electrochem. Soc., 2012, 159: B270-B276.

[190] Lee E, Jang JH, Matin MA, et al. One-step sonochemical syntheses of Ni@Pt core–shell nanoparticles with controlled shape and shell thickness for fuel cell electrocatalyst. Ultrason. Sonochem., 2014, 21: 317-323.

[191] Li C, Imura M, Yamauchi Y Displacement plating of a mesoporous Pt skin onto Co nanochains in a low-concentration surfactant solution. Chem. Eur. J., 2014, 20: 3277-3282.

[192] Zhang S, Hao Y, Su D, et al. Monodisperse core/shell Ni/FePt nanoparticles and their conversion to Ni/Pt to catalyze oxygen reduction. J. Am. Chem. Soc., 2014, 136: 15921-15924.

[193] Jang JH, Lee E, Park J, et al. Rational syntheses of core–shell Fex@Pt nanoparticles for the study of electrocatalytic oxygen reduction reaction. Sci. Rep., 2013, 3: 2872.

[194] Chen Y, Liang Z, Yang F, et al. Ni–Pt core–shell nanoparticles as oxygen reduction electrocatalysts: effect of Pt shell coverage. J. Phys. Chem. C, 2011, 115: 24073-24079.

[195] Zhang XB, Yan JM, Han S, et al. Magnetically recyclable Fe@ Pt core − shell nanoparticles and their use as electrocatalysts for ammonia borane oxidation: the role of crystallinity of the core. J. Am. Chem. Soc., 2009, 131: 2778-2779.

[196] Mani P, Srivastava R, Strasser P Dealloyed Pt–Cu core–shell nanoparticle electrocatalysts for use in PEM fuel cell cathodes. J. Phys. Chem. C, 2008, 112: 2770-2778.

[197] He DS, He D, Wang J, et al. Ultrathin icosahedral Pt-enriched nanocage with excellent oxygen reduction reaction activity. J. Am. Chem. Soc., 2016, 138: 1494-1497.

[198] Sohn Y, Park JH, Kim P, et al. Dealloyed PtCu catalyst as an efficient electrocatalyst in oxygen reduction reaction. Curr. Appl. Phys., 2015, 15: 993-999.

[199] Qiu HJ, Shen X, Wang JQ, et al. Aligned nanoporous Pt–Cu bimetallic microwires with high catalytic activity toward methanol electrooxidation. ACS Catal., 2015, 5: 3779-3785.

[200] Qiu HJ, Xu H, Li X, et al. Core–shell-structured nanoporous PtCu with high Cu content and enhanced catalytic performance. J. Mater. Chem. A, 2015, 3: 7939-7944.

[201] Fu S, Zhu C, Shi Q, et al. Enhanced electrocatalytic activities of three dimensional PtCu@Pt bimetallic alloy nanofoams for oxygen reduction reaction. Catal. Sci. Technol., 2016, 6: 5052-5059.

[202] Zhang K, Yue Q, Chen G, et al. Effects of acid treatment of Pt − Ni alloy nanoparticles@ graphene on the kinetics of the oxygen reduction reaction in acidic and alkaline solutions. J. Phys. Chem. C, 2010, 115: 379-389.

[203] Jia Q, Li J, Caldwell K, et al. Circumventing metal dissolution induced degradation of Pt-alloy catalysts in proton exchange membrane fuel cells: revealing the asymmetric volcano nature of redox catalysis. ACS Catal., 2016, 6: 928-938.

[204] Gan L, Heggen M, O’Malley R, et al. Understanding and controlling nanoporosity formation for improving the stability of bimetallic fuel cell catalysts. Nano Lett., 2013, 13: 1131-1138.

[205] Durst J, Lopez-Haro M, Dubau L, et al. Reversibility of Pt-skin and Pt-skeleton nanostructures in acidic media. J. Phys. Chem. Lett., 2014, 5: 434-439.

[206] Pryadchenko VV, Srabionyan VV, Mikheykina EB, et al. Atomic structure of bimetallic nanoparticles in PtAg/C catalysts: determination of components distribution in the range from disordered alloys to “core–shell” structures. J. Phys. Chem. C, 2015, 119: 3217-3227.

[207] Cheng Y, Shen PK, Jiang SP Enhanced activity and stability of core–shell structured PtRuNi _x electrocatalysts for direct methanol fuel cells. Int. J. Hydrog. Energy, 2016, 41: 1935-1943.

[208] Huang M, Wu C, Guan L Chemical corrosion of PtRuCu₆/C for highly efficient methanol oxidation. J. Power Sources, 2016, 306: 489-494.

[209] Erlebacher J, Aziz MJ, Karma A, et al. Evolution of nanoporosity in dealloying. Nature, 2001, 410: 450-453.

[210] Jiang G, Zhu H, Zhang X, et al. Core/shell face-centered tetragonal FePd/Pd nanoparticles as an efficient non-Pt catalyst for the oxygen reduction reaction. ACS Nano, 2015, 9: 11014-11022.

[211] Li D, Meng F, Wang H, et al. Nanoporous AuPt alloy with low Pt content: a remarkable electrocatalyst with enhanced activity towards formic acid electro-oxidation. Electrochim. Acta, 2016, 190: 852-861.

[212] Zhang Z, Wang Y, Wang X Nanoporous bimetallic Pt–Au alloy nanocomposites with superior catalytic activity towards electro-oxidation of methanol and formic acid. Nanoscale, 2011, 3: 1663-1674.

[213] Raney, M.: Method of preparing catalytic material. US Patent 1,628,190, 10 May 1927

[214] Forty AJ Corrosion micromorphology of noble metal alloys and depletion gilding. Nature, 1979, 282: 597-598.

[215] Mukerjee S, Srinivasan S Vielstich W, Gasteiger HA, Lamm A O₂ reduction and structure-related parameters for supported catalysts. Handbook of Fuel Cells: Fundamentals, Technology and Applications 2003 New York Wiley

[216] Wang D, Yu Y, Xin HL, et al. Tuning oxygen reduction reaction activity via controllable dealloying: a model study of ordered Cu₃Pt/C intermetallic nanocatalysts. Nano Lett., 2012, 12: 5230-5238.

[217] Stamenkovic VR, Mun BS, Mayrhofer KJ, et al. Effect of surface composition on electronic structure, stability, and electrocatalytic properties of Pt-transition metal alloys: Pt-skin versus Pt-skeleton surfaces. J. Am. Chem. Soc., 2006, 128: 8813-8819.

[218] Rudi S, Gan L, Cui C, et al. Electrochemical dealloying of bimetallic ORR nanoparticle catalysts at constant electrode potentials. J. Electrochem. Soc., 2015, 162: F403-F409.

[219] Yu C, Koh S, Leisch JE, et al. Size and composition distribution dynamics of alloy nanoparticle electrocatalysts probed by anomalous small angle X-ray scattering (ASAXS). Faraday Discuss., 2009, 140: 283-296.

[220] Ge X, Chen L, Kang J, et al. A core–shell nanoporous Pt–Cu catalyst with tunable composition and high catalytic activity. Adv. Funct. Mater., 2013, 23: 4156-4162.

[221] Paffett MT, Beery JG, Gottesfeld S Oxygen reduction at Pt_0.65Cr_0.35, Pt_0.2Cr_0.8 and roughened platinum. J. Electrochem. Soc., 1988, 135: 1431-1436.

[222] Snyder J, Asanithi P, Dalton AB, et al. Stabilized nanoporous metals by dealloying ternary alloy precursors. Adv. Mater., 2008, 20: 4883-4886.

[223] Koh S, Strasser P Electrocatalysis on bimetallic surfaces: modifying catalytic reactivity for oxygen reduction by voltammetric surface dealloying. J. Am. Chem. Soc., 2007, 129: 12624-12625.

[224] Strasser P, Koh S, Anniyev T, et al. Lattice-strain control of the activity in dealloyed core–shell fuel cell catalysts. Nat. Chem., 2010, 2: 454-460.

[225] Poochai C, Veerasai W, Somsook E, et al. The influence of copper in dealloyed binary platinum–copper electrocatalysts on methanol electroxidation catalytic activities. Mater. Chem. Phys., 2015, 163: 317-330.

[226] El-Deeb H, Bron M Electrochemical dealloying of PtCu/CNT electrocatalysts synthesized by NaBH₄-assisted polyol-reduction: influence of preparation parameters on oxygen reduction activity. Electrochim. Acta, 2015, 164: 315-322.

[227] Heggen M, Oezaslan M, Houben L, et al. Formation and analysis of core–shell fine structures in Pt bimetallic nanoparticle fuel cell electrocatalysts. J. Phys. Chem. C, 2012, 116: 19073-19083.

[228] Oezaslan M, Heggen M, Strasser P Size-dependent morphology of dealloyed bimetallic catalysts: linking the nano to the macro scale. J. Am. Chem. Soc., 2012, 134: 514-524.

[229] Gan L, Heggen M, Rudi S, et al. Core–shell compositional fine structures of dealloyed Pt _xNi_1−x nanoparticles and their impact on oxygen reduction catalysis. Nano Lett., 2012, 12: 5423-5430.

[230] Baldizzone C, Gan L, Hodnik N, et al. Stability of dealloyed porous Pt/Ni nanoparticles. ACS Catal., 2015, 5: 5000-5007.

[231] Snyder J, McCue I, Livi K, et al. Structure/processing/properties relationships in nanoporous nanoparticles as applied to catalysis of the cathodic oxygen reduction reaction. J. Am. Chem. Soc., 2012, 134: 8633-8645.

[232] Carpenter MK, Moylan TE, Kukreja RS, et al. Solvothermal synthesis of platinum alloy nanoparticles for oxygen reduction electrocatalysis. J. Am. Chem. Soc., 2012, 134: 8535-8542.

[233] Wang C, Chi M, Wang G, et al. Correlation between surface chemistry and electrocatalytic properties of monodisperse Pt _xNi_1−x Nanoparticles. Adv. Funct. Mater., 2011, 21: 147-152.

[234] Rudi S, Tuaev X, Strasser P Electrocatalytic oxygen reduction on dealloyed Pt_1−xNi _x alloy nanoparticle electrocatalysts. Electrocatalysis, 2012, 3: 265-273.

[235] Tuaev X, Rudi S, Petkov V, et al. In situ study of atomic structure transformations of Pt–Ni nanoparticle catalysts during electrochemical potential cycling. ACS Nano, 2013, 7: 5666-5674.

[236] Cui C, Gan L, Heggen M, et al. Compositional segregation in shaped Pt alloy nanoparticles and their structural behaviour during electrocatalysis. Nat. Mater., 2013, 12: 765-771.

[237] Srivastava R, Mani P, Hahn N, et al. Efficient oxygen reduction fuel cell electrocatalysis on voltammetrically dealloyed Pt–Cu–Co nanoparticles. Angew. Chem. Int. Ed., 2007, 46: 8988-8991.

[238] Wang M, He Y, Li R, et al. Electrochemical activated PtAuCu alloy nanoparticle catalysts for formic acid, methanol and ethanol electro-oxidation. Electrochim. Acta, 2015, 178: 259-269.

[239] Williams D, Newman R, Song Q, et al. Passivity breakdown and pitting corrosion of binary alloys. Nature, 1991, 350: 216-219.

[240] Erlebacher J, Sieradzki K Pattern formation during dealloying. Scr. Mater., 2003, 49: 991-996.

[241] Hayes JR, Hodge AM, Biener J, et al. Monolithic nanoporous copper by dealloying Mn–Cu. J. Mater. Res., 2011, 21: 2611-2616.

[242] Keir D, Pryor M The dealloying of copper–manganese alloys. J. Electrochem. Soc., 1980, 127: 2138-2144.

[243] Strasser P, et al. Vielstich W, Lamm A, Gasteiger HA, et al. Dealloyed Pt bimetallic electrocatalysts for oxygen reduction. Handbook of Fuel Cells 2010 Hoboken Wiley

[244] Strasser P Dealloyed core–shell fuel cell electrocatalysts. Rev. Chem. Eng., 2009, 25: 255-295.

[245] Hasché F, Oezaslan M, Strasser P Activity, stability, and degradation mechanisms of dealloyed PtCu₃ and PtCo₃ nanoparticle fuel cell catalysts. ChemCatChem, 2011, 3: 1805-1813.

[246] Podlovchenko BI, Maksimov YM, Utkin AG Formation of the core–shell structure in the Pd–Ag system by electroleaching of the alloy. Electrocatalytic properties. Russ. J. Electrochem., 2015, 51: 891-898.

[247] Kim J, Lee Y, Sun S Structurally ordered FePt nanoparticles and their enhanced catalysis for oxygen reduction reaction. J. Am. Chem. Soc., 2010, 132: 4996-4997.

[248] Koh S, Yu C, Mani P, et al. Activity of ordered and disordered Pt–Co alloy phases for the electroreduction of oxygen in catalysts with multiple coexisting phases. J. Power Sources, 2007, 172: 50-56.

[249] Liu Y, Lowe MA, DiSalvo FJ, et al. Kinetic stabilization of ordered intermetallic phases as fuel cell anode materials. J. Phys. Chem. C, 2010, 114: 14929-14938.

[250] Mukerjee S, Srinivasan S, Soriaga MP, et al. Role of structural and electronic properties of Pt and Pt alloys on electrocatalysis of oxygen reduction An in situ XANES and EXAFS investigation. J. Electrochem. Soc., 1995, 142: 1409-1422.

[251] Gan L, Rudi S, Cui C, et al. Size-controlled synthesis of sub-10 nm PtNi₃ alloy nanoparticles and their unusual volcano-shaped size effect on ORR electrocatalysis. Small, 2016, 12: 3189-3196.

[252] Rebak R, Crook P Improved pitting and crevice corrosion resistance of nickel and cobalt based alloys. Proc. Electrochem. Soc., 1999, 98–17: 289-302.

[253] Davis JR Corrosion: Understanding the Basics 2000 Geauga County ASM International

[254] Pickering HW Characteristic features of alloy polarization curves. Corros. Sci., 1983, 23: 1107-1120.

[255] Liu A, Geng H, Xu C, et al. A three-dimensional hierarchical nanoporous PdCu alloy for enhanced electrocatalysis and biosensing. Anal. Chim. Acta, 2011, 703: 172-178.

[256] Xu C, Su J, Xu X, et al. Low temperature CO oxidation over unsupported nanoporous gold. J. Am. Chem. Soc., 2007, 129: 42-43.

[257] Kim KT, Kim YG, Chung JS Effect of surface roughening on the catalytic activity of Pt–Cr electrocatalysts for the oxygen reduction in phosphoric acid fuel cell. J. Electrochem. Soc., 1995, 142: 1531-1538.

[258] Wang W, Ji S, Wang H, et al. Nanoporous PdNi/C electrocatalyst prepared by dealloying high-Ni-content PdNi alloy for formic acid oxidation. Fuel Cells, 2012, 12: 1129-1133.

[259] Xu C, Wang L, Wang R, et al. Nanotubular mesoporous bimetallic nanostructures with enhanced electrocatalytic performance. Adv. Mater., 2009, 21: 2165-2169.

[260] Chen X, Si C, Gao Y, et al. Multi-component nanoporous platinum–ruthenium–copper–osmium–iridium alloy with enhanced electrocatalytic activity towards methanol oxidation and oxygen reduction. J. Power Sources, 2015, 273: 324-332.

[261] Carmo M, Sekol RC, Ding S, et al. Bulk metallic glass nanowire architecture for electrochemical applications. ACS Nano, 2011, 5: 2979-2983.

[262] Baumgärtner M, Raub J The electrodeposition of platinum and platinum alloys. Platin. Met. Rev., 1988, 32: 188-197.

[263] Sardar R, Funston AM, Mulvaney P, et al. Gold nanoparticles: past, present, and future. Langmuir ACS J. Surf. Colloids, 2009, 25: 13840-13851.

[264] Ferrando R, Jellinek J, Johnston RL Nanoalloys: from theory to applications of alloy clusters and nanoparticles. Chem. Rev., 2008, 108: 845-910.

[265] Bönnemann H, Richards RM Nanoscopic metal particles − synthetic methods and potential applications. Eur. J. Inorg. Chem., 2001, 2001: 2455-2480.

[266] Bliznakov S, Vukmirovic M, Adzic R Hermans S, de Bocarme TV Electrochemical atomic-level controlled syntheses of electrocatalysts for the oxygen reduction reaction. Atomically-Precise Methods for Synthesis of Solid Catalysts 2014 London Royal Society of Chemistry 144 166

[267] Li GR, Xu H, Lu XF, et al. Electrochemical synthesis of nanostructured materials for electrochemical energy conversion and storage. Nanoscale, 2013, 5: 4056-4069.

[268] Bard AJ, Faulkner LR, Leddy J, et al. Electrochemical Methods: Fundamentals and Applications 1980 New York Wiley

[269] Zhang H, Jin M, Xia Y Enhancing the catalytic and electrocatalytic properties of Pt-based catalysts by forming bimetallic nanocrystals with Pd. Chem. Soc. Rev., 2012, 41: 8035-8049.

[270] Sasaki K, Naohara H, Cai Y, et al. Core-protected platinum monolayer shell high-stability electrocatalysts for fuel-cell cathodes. Angew. Chem. Int. Ed., 2010, 49: 8602-8607.

[271] Bewick A, Thomas B Optical and electrochemical studies of the underpotential deposition of metals part I. Thallium deposition on single crystal silver electrodes. J. Electroanal. Chem. Interfacial Electrochem., 1975, 65: 911-931.

[272] Bewick A, Thomas B Optical and electrochemical studies of the under-potential deposition of metals: part III. Lead deposition on silver single crystals. J. Electroanal. Chem. Interfacial Electrochem., 1977, 84: 127-140.

[273] Adzic R, Yeager E, Cahan B Optical and electrochemical studies of underpotential deposition of lead on gold evaporated and single-crystal electrodes. J. Electrochem. Soc., 1974, 121: 474-484.

[274] Herrero E, Buller LJ, Abruña HD Underpotential deposition at single crystal surfaces of Au, Pt, Ag and other materials. Chem. Rev., 2001, 101: 1897-1930.

[275] Brankovic S, Wang J, Adzic R New methods of controlled monolayer-to-multilayer deposition of Pt for designing electrocatalysts at an atomic level. J. Serb. Chem. Soc., 2001, 66: 887-898.

[276] Brankovic S, Wang J, Adžić R Metal monolayer deposition by replacement of metal adlayers on electrode surfaces. Surf. Sci., 2001, 474: L173-L179.

[277] Mrozek MF, Xie Y, Weaver MJ Surface-enhanced Raman scattering on uniform platinum-group overlayers: preparation by redox replacement of underpotential-deposited metals on gold. Anal. Chem., 2001, 73: 5953-5960.

[278] Park S, Yang P, Corredor P, et al. Transition metal-coated nanoparticle films: vibrational characterization with surface-enhanced Raman scattering. J. Am. Chem. Soc., 2002, 124: 2428-2429.

[279] Zhang J, Lima F, Shao M, et al. Platinum monolayer on nonnoble metal-noble metal core–shell nanoparticle electrocatalysts for O₂ reduction. J. Phys. Chem. B, 2005, 109: 22701-22704.

[280] Van Brussel M, Kokkinidis G, Vandendael I, et al. High performance gold-supported platinum electrocatalyst for oxygen reduction. Electrochem. Commun., 2002, 4: 808-813.

[281] Van Brussel M, Kokkinidis G, Hubin A, et al. Oxygen reduction at platinum modified gold electrodes. Electrochim. Acta, 2003, 48: 3909-3919.

[282] Koenigsmann C, Santulli AC, Gong K, et al. Enhanced electrocatalytic performance of processed, ultrathin, supported Pd–Pt core–shell nanowire catalysts for the oxygen reduction reaction. J. Am. Chem. Soc., 2011, 133: 9783-9795.

[283] Park YK, Yoo SH, Park S Three-dimensional Pt-coated Au nanoparticle arrays: applications for electrocatalysis and surface-enhanced Raman scattering. Langmuir ACS J. Surf. Colloids, 2008, 24: 4370-4375.

[284] Zhai J, Huang M, Dong S Electrochemical designing of Au/Pt core shell nanoparticles as nanostructured catalyst with tunable activity for oxygen reduction. Electroanalysis, 2007, 19: 506-509.

[285] Cheng S, Rettew RE, Sauerbrey M, et al. Architecture-dependent surface chemistry for Pt monolayers on carbon-supported Au. ACS Appl. Mater. Interfaces., 2011, 3: 3948-3956.

[286] Iyyamperumal R, Zhang L, Henkelman G, et al. Efficient electrocatalytic oxidation of formic acid using Au@ Pt dendrimer-encapsulated nanoparticles. J. Am. Chem. Soc., 2013, 135: 5521-5524.

[287] Fayette M, Liu Y, Bertrand D, et al. From Au to Pt via surface limited redox replacement of Pb UPD in one-cell configuration. Langmuir ACS J. Surf. Colloids, 2011, 27: 5650-5658.

[288] Sasaki K, Naohara H, Choi Y, et al. Highly stable Pt monolayer on PdAu nanoparticle electrocatalysts for the oxygen reduction reaction. Nat. Commun., 2012, 3: 1115.

[289] Xing Y, Cai Y, Vukmirovic MB, et al. Enhancing oxygen reduction reaction activity via Pd − Au alloy sublayer mediation of Pt monolayer electrocatalysts. J. Phys. Chem. Lett., 2010, 1: 3238-3242.

[290] Sun Y, Hsieh YC, Chang LC, et al. Enhancing oxygen reduction reaction for oxygen reduction reaction in acidic electrolytes. J. Power Sources, 2015, 277: 116-123.

[291] Ghosh T, Vukmirovic MB, DiSalvo FJ, et al. Intermetallics as novel supports for Pt monolayer O₂ reduction electrocatalysts: potential for significantly improving properties. J. Am. Chem. Soc., 2009, 132: 906-907.

[292] Yang L, Vukmirovic MB, Su D, et al. Tuning the catalytic activity of Ru@ Pt core–shell nanoparticles for the oxygen reduction reaction by varying the shell thickness. J. Phys. Chem. C, 2013, 117: 1748-1753.

[293] Gnanaprakasam P, Jeena S, Selvaraju T Hierarchical electroless Pt deposition at Au decorated reduced graphene oxide via a galvanic exchanged process: an electrocatalytic nanocomposite with enhanced mass activity for methanol and ethanol oxidation. J. Mater. Chem. A, 2015, 3: 18010-18018.

[294] Nan H, Tian X, Luo J, et al. A core–shell Pd₁Ru₁Ni₂@Pt/C catalyst with a ternary alloy core and Pt monolayer: enhanced activity and stability towards the oxygen reduction reaction by the addition of Ni. J. Mater. Chem. A, 2016, 4: 847-855.

[295] Tsai HC, Hsieh YC, Yu TH, et al. DFT study of oxygen reduction reaction on Os/Pt core–shell catalysts validated by electrochemical experiment. ACS Catal., 2015, 5: 1568-1580.

[296] Brimaud S, Behm RJ Electrodeposition of a Pt monolayer film: using kinetic limitations for atomic layer epitaxy. J. Am. Chem. Soc., 2013, 135: 11716-11719.

[297] Wang JX, Inada H, Wu L, et al. Oxygen reduction on well-defined core − shell nanocatalysts: particle size, facet, and Pt shell thickness effects. J. Am. Chem. Soc., 2009, 131: 17298-17302.

[298] Zhou WP, Sasaki K, Su D, et al. Gram-scale-synthesized Pd₂Co-supported Pt monolayer electrocatalysts for oxygen reduction reaction. J. Phys. Chem. C, 2010, 114: 8950-8957.

[299] Sasaki K, Wang JX, Naohara H, et al. Recent advances in platinum monolayer electrocatalysts for oxygen reduction reaction: scale-up synthesis, structure and activity of Pt shells on Pd cores. Electrochim. Acta, 2010, 55: 2645-2652.

[300] Jin Y, Shen Y, Dong S Electrochemical design of ultrathin platinum-coated gold nanoparticle monolayer films as a novel nanostructured electrocatalyst for oxygen reduction. J. Phys. Chem. B, 2004, 108: 8142-8147.

[301] Zhang J, Mo Y, Vukmirovic M, et al. Platinum monolayer electrocatalysts for O₂ reduction: Pt monolayer on Pd (111) and on carbon-supported Pd nanoparticles. J. Phys. Chem. B, 2004, 108: 10955-10964.

[302] Yu Y, Lim KH, Wang JY, et al. CO adsorption behavior on decorated Pt@Au nanoelectrocatalysts: a combined experimental and DFT theoretical calculation study. J. Phys. Chem. C, 2012, 116: 3851-3856.

[303] Yu Y, Hu Y, Liu X, et al. The study of Pt@Au electrocatalyst based on Cu underpotential deposition and Pt redox replacement. Electrochim. Acta, 2009, 54: 3092-3097.

[304] Wang W, Zhao Y, Ding Y 2D ultrathin core − shell Pd@Pt(monolayer) nanosheets: defect-mediated thin film growth and enhanced oxygen reduction performance. Nanoscale, 2015, 7: 11934-11939.

[305] Takimoto D, Ohnishi T, Nutariya J, et al. Ru-core@Pt-shell nanosheet for fuel cell electrocatalysts with high activity and durability. J. Catal., 2017, 345: 207-215.

[306] Carino EV, Crooks RM Characterization of Pt@ Cu core@ shell dendrimer-encapsulated nanoparticles synthesized by Cu underpotential deposition. Langmuir ACS J. Surf. Colloids, 2011, 27: 4227-4235.

[307] Mahesh I, Sarkar A Electrochemical study of oxygen reduction on carbon supported core − shell platinum − gold electrocatalyst with tuneable surface composition of gold. ChemElectroChem, 2016, 3: 836-845.

[308] Carino EV, Kim HY, Henkelman G, et al. Site-selective Cu deposition on Pt dendrimer-encapsulated nanoparticles: correlation of theory and experiment. J. Am. Chem. Soc., 2012, 134: 4153-4162.

[309] Kim YG, Kim JY, Vairavapandian D, et al. Platinum nanofilm formation by EC-ALE via redox replacement of UPD copper: studies using in situ scanning tunneling microscopy. J. Phys. Chem. B, 2006, 110: 17998-18006.

[310] Sieradzki K, Dimitrov N Electrochemical defect-mediated thin-film growth. Science, 1999, 284: 138-141.

[311] Wang J, Ocko B, Adzic R Overpotential deposition of Ag monolayer and bilayer on Au (111) mediated by Pb adlayer underpotential deposition/stripping cycles. Surf. Sci., 2003, 540: 230-236.

[312] Yang T, Cao G, Huang Q, et al. Surface-limited synthesis of Pt nanocluster decorated Pd hierarchical structures with enhanced electrocatalytic activity toward oxygen reduction reaction. ACS Appl. Mater. Interfaces., 2015, 7: 17162-17170.

[313] Choi KH, Kim HS, Lee TH Electrode fabrication for proton exchange membrane fuel cells by pulse electrodeposition. J. Power Sources, 1998, 75: 230-235.

[314] Cheh H The limiting rate of deposition by P-R plating. J. Electrochem. Soc., 1971, 118: 1132-1134.

[315] Lu X, Luo F, Song H, et al. Pulse electrodeposition to prepare core–shell structured AuPt@Pd/C catalyst for formic acid fuel cell application. J. Power Sources, 2014, 246: 659-666.

[316] Ibl N Some theoretical aspects of pulse electrolysis. Surf. Technol., 1980, 10: 81-104.

[317] Reddy, V.N.R.K., Anderson, E.B., Taylor, E.J.: High utilization supported catalytic metal-containing gas-diffusion electrode, process for making it, and cells utilizing it. US Patent 5,084,144, 28 Jan 1992

[318] Verbrugge MW Selective electrodeposition of catalyst within membrane-electrode structures. J. Electrochem. Soc., 1994, 141: 46-53.

[319] Dhar HP On solid polymer fuel cells. J. Electroanal. Chem., 1993, 357: 237-250.

[320] Liu J, Wang X, Lin Z, et al. Shape-controllable pulse electrodeposition of ultrafine platinum nanodendrites for methanol catalytic combustion and the investigation of their local electric field intensification by electrostatic force microscope and finite element method. Electrochim. Acta, 2014, 136: 66-74.

[321] Wei ZD, Chan SH Electrochemical deposition of PtRu on an uncatalyzed carbon electrode for methanol electrooxidation. J. Electroanal. Chem., 2004, 569: 23-33.

[322] Bo Z, Hu D, Kong J, et al. Performance of vertically oriented graphene supported platinum–ruthenium bimetallic catalyst for methanol oxidation. J. Power Sources, 2015, 273: 530-537.

[323] Tsai MC, Yeh TK, Tsai CH Methanol oxidation efficiencies on carbon-nanotube-supported platinum and platinum–ruthenium nanoparticles prepared by pulsed electrodeposition. Int. J. Hydrog. Energy, 2011, 36: 8261-8266.

[324] Coutanceau C, Rakotondrainibe A, Lima A, et al. Preparation of Pt–Ru bimetallic anodes by galvanostatic pulse electrodeposition: characterization and application to the direct methanol fuel cell. J. Appl. Electrochem., 2004, 34: 61-66.

[325] Chou HY, Hsieh CK, Tsai MC, et al. Pulse electrodeposition of Pt and Pt–Ru methanol-oxidation nanocatalysts onto carbon nanotubes in citric acid aqueous solutions. Thin Solid Films, 2015, 584: 98-102.

[326] Nagaiah TC, Maljusch A, Chen X, et al. Visualization of the local catalytic activity of electrodeposited Pt–Ag catalysts for oxygen reduction by means of SECM. ChemPhysChem, 2009, 10: 2711-2718.

[327] Schwamborn S, Stoica L, Schuhmann W Activation/inhibition effects during the coelectrodeposition of PtAg nanoparticles: application for ORR in alkaline media. ChemPhysChem, 2011, 12: 1741-1746.

[328] Kulp C, Chen X, Puschhof A, et al. Electrochemical synthesis of core–shell catalysts for electrocatalytic applications. ChemPhysChem, 2010, 11: 2854-2861.

[329] Tian X, Luo J, Nan H, et al. Transition metal nitride coated with atomic layers of Pt as a low-cost, highly stable electrocatalyst for the oxygen reduction reaction. J. Am. Chem. Soc., 2016, 138: 1575-1583.

[330] Deng YJ, Tripkovic V, Rossmeisl J, et al. Oxygen reduction reaction on Pt overlayers deposited onto a gold film: ligand, strain, and ensemble effect. ACS Catal., 2016, 6: 671-676.

[331] Chen D, Li Y, Liao S, et al. Ultra-high-performance core–shell structured Ru@Pt/C catalyst prepared by a facile pulse electrochemical deposition method. Sci. Rep., 2015, 5: 11604.

[332] Dang D, Liao S, Luo F, et al. A pulse electrochemical deposition method to prepare membrane electrode assemblies with ultra-low anode Pt loadings through in situ construction of active core–shell nanoparticles on an electrode. J. Power Sources, 2014, 260: 27-33.

[333] Kulp C, Gillmeister K, Widdra W, et al. Synthesis of Cu_corePt_shell nanoparticles as model structures for core–shell electrocatalysts by direct platinum electrodeposition on copper. ChemPhysChem, 2013, 14: 1205-1210.

[334] Dang D, Zou H, Xiong Z, et al. High-performance, ultralow platinum membrane electrode assembly fabricated by in situ deposition of a Pt shell layer on carbon-supported Pd nanoparticles in the catalyst layer using a facile pulse electrodeposition approach. ACS Catal., 2015, 5: 4318-4324.

[335] Huang C, Bunmi Odetola C, Rodgers M Nanoparticle seeded pulse electrodeposition for preparing high performance Pt/C electrocatalysts. Appl. Catal. A, 2015, 499: 55-65.

[336] Ding LX, Li GR, Wang ZL, et al. Porous Ni@ Pt core–shell nanotube array electrocatalyst with high activity and stability for methanol oxidation. Chem. Eur. J., 2012, 18: 8386-8391.

[337] Ye SH, Feng JX, Wang AL, et al. Multi-layered Pt/Ni nanotube arrays with enhanced catalytic performance for methanol electrooxidation. J. Mater. Chem. A, 2015, 3: 23201-23206.

[338] Wang Z, Xie W, Zhang F, et al. Facile synthesis of PtPdPt nanocatalysts for methanol oxidation in alkaline solution. Electrochim. Acta, 2016, 192: 400-406.

[339] Gupta R, Guin SK, Aggarwal SK Electrocrystallization of palladium (Pd) nanoparticles on platinum (Pt) electrode and its application for electro-oxidation of formic acid and methanol. Electrochim. Acta, 2014, 116: 314-320.

[340] Suntivich J, Xu Z, Carlton CE, et al. Surface composition tuning of Au–Pt bimetallic nanoparticles for enhanced carbon monoxide and methanol electro-oxidation. J. Am. Chem. Soc., 2013, 135: 7985-7991.

[341] Campbell CT Bimetallic surface chemistry. Annu. Rev. Phys. Chem., 1990, 41: 775-837.

[342] Brongersma H, Sparnaay M, Buck T Surface segregation in Cu–Ni and Cu–Pt alloys; a comparison of low-energy ion-scattering results with theory. Surf. Sci., 1978, 71: 657-678.

[343] Chelikowsky JR Predictions for surface segregation in intermetallic alloys. Surf. Sci., 1984, 139: L197-L203.

[344] Christensen A, Stoltze P, Norskov J Size dependence of phase separation in small bimetallic clusters. J. Phys.: Condens. Matter, 1995, 7: 1047.

[345] Hansen PL, Molenbroek AM, Ruban AV Alloy formation and surface segregation in zeolite-supported Pt–Pd bimetallic catalysts. J. Phys. Chem. B, 1997, 101: 1861-1868.

[346] Van den Oetelaar L, Nooij O, Oerlemans S, et al. Surface segregation in supported Pd–Pt nanoclusters and alloys. J. Phys. Chem. B, 1998, 102: 3445-3455.

[347] Tao F, Grass ME, Zhang Y, et al. Reaction-driven restructuring of Rh–Pd and Pt–Pd core–shell nanoparticles. Science, 2008, 322: 932-934.

[348] Brodsky CN, Young AP, Ng KC, et al. Electrochemically induced surface metal migration in well-defined core–shell nanoparticles and its general influence on electrocatalytic reactions. ACS Nano, 2014, 8: 9368-9378.

[349] Hwang BJ, Sarma LS, Chen JM, et al. Structural models and atomic distribution of bimetallic nanoparticles as investigated by X-ray absorption spectroscopy. J. Am. Chem. Soc., 2005, 127: 11140-11145.

[350] Liu CW, Chen HS, Lai CM, et al. Promotion of oxygen reduction reaction durability of carbon-supported PtAu catalysts by surface segregation and TiO₂ addition. ACS Appl. Mater. Interfaces., 2014, 6: 1589-1594.

[351] Chung YH, Chung DY, Jung N, et al. Origin of the enhanced electrocatalysis for thermally controlled nanostructure of bimetallic nanoparticles. J. Phys. Chem. C, 2014, 118: 9939-9945.

[352] Ahmadi M, Behafarid F, Cui C, et al. Long-range segregation phenomena in shape-selected bimetallic nanoparticles: chemical state effects. ACS Nano, 2013, 7: 9195-9204.

[353] Liu H, Dou M, Wang F, et al. Ordered intermetallic PtFe@ Pt core–shell nanoparticles supported on carbon nanotubes with superior activity and durability as oxygen reduction reaction electrocatalysts. RSC Adv., 2015, 5: 66471-66475.

[354] Guo H, Liu X, Bai C, et al. Effect of component distribution and nanoporosity in CuPt nanotubes on electrocatalysis of the oxygen reduction reaction. Chemsuschem, 2015, 8: 486-494.

[355] Liu Z, Jackson GS, Eichhorn BW Tuning the CO-tolerance of Pt–Fe bimetallic nanoparticle electrocatalysts through architectural control. Energy Environ. Sci., 2011, 4: 1900-1903.

[356] Budiman AH, Purwanto WW, Dewi EL, et al. Understanding adsorbate-induced surface segregation in PtCo/C electrocatalyst. Asia-Pac. J. Chem. Eng., 2012, 7: 604-612.

[357] Lee KS, Park HY, Ham HC, et al. Reversible surface segregation of Pt in a Pt₃Au/C catalyst and its effect on the oxygen reduction reaction. J. Phys. Chem. C, 2013, 117: 9164-9170.

[358] Wei YC, Liu CW, Chang WJ, et al. Promotion of Pt–Ru/C catalysts driven by heat treated induced surface segregation for methanol oxidation reaction. J. Alloys Compd., 2011, 509: 535-541.

[359] Xiong Y, Xiao L, Yang Y, et al. High-loading intermetallic Pt₃Co/C core–shell nanoparticles as enhanced activity electrocatalysts toward the oxygen reduction reaction (ORR). Chem. Mater., 2018, 30: 1532-1539.

[360] Cui CH, Li HH, Liu XJ, et al. Surface composition and lattice ordering-controlled activity and durability of CuPt electrocatalysts for oxygen reduction reaction. ACS Catal., 2012, 2: 916-924.

[361] Puurunen RL Surface chemistry of atomic layer deposition: a case study for the trimethylaluminum/water process. J. Appl. Phys., 2005, 97: 121301.

[362] Ritala M, Leskelä M Atomic layer epitaxy: a valuable tool for nanotechnology?. Nanotechnology, 1999, 10: 19.

[363] Leskela M, Ritala M Atomic layer deposition chemistry: recent developments and future challenges. Angew. Chem. Int. Ed., 2003, 42: 5548-5554.

[364] Kim H, Maeng WJ Applications of atomic layer deposition to nanofabrication and emerging nanodevices. Thin Solid Films, 2009, 517: 2563-2580.

[365] Comstock DJ, Christensen ST, Elam JW, et al. Tuning the composition and nanostructure of Pt/Ir films via anodized aluminum oxide templated atomic layer deposition. Adv. Funct. Mater., 2010, 20: 3099-3105.

[366] Cao K, Zhu Q, Shan B, et al. Controlled synthesis of Pd/Pt core shell nanoparticles using area-selective atomic layer deposition. Sci. Rep., 2015, 5: 8470.

[367] Cao K, Liu X, Zhu Q, et al. Atomically controllable Pd@Pt core–shell nanoparticles towards preferential oxidation of CO in hydrogen reactions modulated by platinum shell thickness. ChemCatChem, 2016, 8: 326-330.

[368] Weber M, Verheijen M, Bol A, et al. Sub-nanometer dimensions control of core/shell nanoparticles prepared by atomic layer deposition. Nanotechnology, 2015, 26: 094002.

[369] Jiang X, Gür TM, Prinz FB, et al. Atomic layer deposition (ALD) co-deposited Pt–Ru binary and pt skin catalysts for concentrated methanol oxidation. Chem. Mater., 2010, 22: 3024-3032.

[370] Santasalo-Aarnio A, Sairanen E, Arán-Ais RM, et al. The activity of ALD-prepared PtCo catalysts for ethanol oxidation in alkaline media. J. Catal., 2014, 309: 38-48.

[371] Sairanen E, Figueiredo MC, Karinen R, et al. Atomic layer deposition in the preparation of Bi-metallic, platinum-based catalysts for fuel cell applications. Appl. Catal. B, 2014, 148–149: 11-21.

[372] Johansson AC, Larsen JV, Verheijen MA, et al. Electrocatalytic activity of atomic layer deposited Pt–Ru catalysts onto N-doped carbon nanotubes. J. Catal., 2014, 311: 481-486.

[373] Johansson AC, Yang RB, Haugshøj KB, et al. Ru-decorated Pt nanoparticles on N-doped multi-walled carbon nanotubes by atomic layer deposition for direct methanol fuel cells. Int. J. Hydrog. Energy, 2013, 38: 11406-11414.

[374] Gould TD, Montemore MM, Lubers AM, et al. Enhanced dry reforming of methane on Ni and Ni–Pt catalysts synthesized by atomic layer deposition. Appl. Catal. A, 2015, 492: 107-116.

[375] Kawasaki M, Hsiao CN, Yang JR, et al. Structural investigation of Ru/Pt nanocomposite films prepared by plasma-enhanced atomic layer depositions. Micron, 2015, 74: 8-14.

[376] Hsu IJ, Chen JG, Jiang X, et al. Atomic layer deposition synthesis and evaluation of core–shell Pt–WC electrocatalysts. J. Vac. Sci. Technol. A Vac. Surf. Films, 2015, 33: 01A129.

[377] Jeong HJ, Kim JW, Bae K, et al. Platinum–ruthenium heterogeneous catalytic anodes prepared by atomic layer deposition for use in direct methanol solid oxide fuel cells. ACS Catal., 2015, 5: 1914-1921.

[378] Jeong HJ, Kim JW, Jang DY, et al. Atomic layer deposition of ruthenium surface-coating on porous platinum catalysts for high-performance direct ethanol solid oxide fuel cells. J. Power Sources, 2015, 291: 239-245.

[379] Shim JH, Jiang X, Bent S, et al. DeGendt S, Delabie A, Kang SB, et al. Metal alloy catalysts with Pt surface coating by atomic layer deposition for intermediate temperature ceramic fuel cells. ECS Transactions 2009 Pennington Electrochemical Society Inc. 323 332

[380] Hoover RR, Tolmachev YV Electrochemical properties of Pt coatings on Ni prepared by atomic layer deposition. J. Electrochem. Soc., 2009, 156: A37-A43.

[381] Clancey JW, Cavanagh AS, Kukreja RS, et al. Atomic layer deposition of ultrathin platinum films on tungsten atomic layer deposition adhesion layers: application to high surface area substrates. J. Vac. Sci. Technol. A Vac. Surf. Films, 2015, 33: 01A130.

[382] Sugioka D, Kameyama T, Kuwabata S, et al. Formation of a Pt-decorated Au nanoparticle monolayer floating on an ionic liquid by the ionic liquid/metal sputtering method and tunable electrocatalytic activities of the resulting monolayer. ACS Appl. Mater. Interfaces., 2016, 8: 10874-10883.

[383] Grigoriev SA, Fedotov AA, Murzin VY, et al. Study of nanostructured electrocatalysts synthesized by the platinum magnetron–ion-beam sputtering onto metallized nanostructured carbonaceous support. Russ. J. Electrochem., 2015, 51: 807-819.

[384] Fedotov AA, Grigoriev SA, Millet P, et al. Plasma-assisted Pt and Pt–Pd nano-particles deposition on carbon carriers for application in PEM electrochemical cells. Int. J. Hydrog. Energy, 2013, 38: 8568-8574.

[385] Grigoriev S, Fedotov A, Martemianov S, et al. Synthesis of nanostructural electrocatalytic materials on various carbon substrates by ion plasma sputtering of platinum metals. Russ. J. Electrochem., 2014, 50: 638-646.

[386] Galhenage RP, Xie K, Diao W, et al. Platinum–ruthenium bimetallic clusters on graphite: a comparison of vapor deposition and electroless deposition methods. Phys. Chem. Chem. Phys., 2015, 17: 28354-28363.

[387] Gasda MD, Eisman GA, Gall D Sputter-deposited Pt/CrN nanoparticle PEM fuel cell cathodes: limited proton conductivity through electrode dewetting. J. Electrochem. Soc., 2010, 157: B71.

[388] Kariuki NN, Cansizoglu MF, Begum M, et al. SAD–GLAD Pt–Ni@Ni nanorods as highly active oxygen reduction reaction electrocatalysts. ACS Catal., 2016, 6: 3478-3485.

[389] Cha IY, Ahn M, Yoo SJ, et al. Facile synthesis of carbon supported metal nanoparticles via sputtering onto a liquid substrate and their electrochemical application. RSC Adv., 2014, 4: 38575-38580.

[390] Thomas FS, Masel RI Formic acid decomposition on palladium-coated Pt (110). Surf. Sci., 2004, 573: 169-175.

[391] Kelly P, Arnell R Magnetron sputtering: a review of recent developments and applications. Vacuum, 2000, 56: 159-172.

[392] Lee CH, Chen YS, Liu LJ, et al. The structural transition from epitaxial Fe/Pt multilayers to an ordered FePt film using low energy ion beam sputtering deposition with no buffer layer. Thin Solid Films, 2014, 570: 288-292.

[393] Wu J, Pan Y, Chen L, et al. Microstructure transformation and interface structure of Co/Pt nano-multilayers prepared by ion beam sputtering deposition (IBSD). Surf. Coat. Technol., 2004, 176: 357-364.

[394] Weng KW, Han S, Chen YL, et al. Characteristics of DMFC electrodes improve by the MPII Pt–Ru catalysts. Surf. Coat. Technol., 2007, 201: 6557-6560.

[395] Fateev V, Alekseeva O, Lutikova E, et al. New physical technologies for catalyst synthesis and anticorrosion protection. Int. J. Hydrog. Energy, 2016, 41: 10515-10521.

[396] Toda T, Igarashi H, Uchida H, et al. Enhancement of the electroreduction of oxygen on Pt alloys with Fe, Ni, and Co. J. Electrochem. Soc., 1999, 146: 3750-3756.

[397] Sokhoreva VV, Golovkov VM Formation of a fuel-cell catalyst layer with a low platinum content. Pet. Chem., 2015, 55: 315-317.

[398] Wender H, de Oliveira LF, Migowski P, et al. Ionic liquid surface composition controls the size of gold nanoparticles prepared by sputtering deposition. J. Phys. Chem. C, 2010, 114: 11764-11768.

[399] Yoshida H, Kawamoto K, Kubo H, et al. Nanoparticle-dispersed liquid crystals fabricated by sputter doping. Adv. Mater., 2010, 22: 622-626.

[400] Hirano M, Enokida K, Okazaki K, et al. Composition-dependent electrocatalytic activity of AuPd alloy nanoparticles prepared via simultaneous sputter deposition into an ionic liquid. Phys. Chem. Chem. Phys., 2013, 15: 7286-7294.

[401] Wang L, Yamauchi Y Metallic nanocages: synthesis of bimetallic Pt–Pd hollow nanoparticles with dendritic shells by selective chemical etching. J. Am. Chem. Soc., 2013, 135: 16762-16765.

[402] Shao M, Shoemaker K, Peles A, et al. Pt monolayer on porous Pd − Cu alloys as oxygen reduction electrocatalysts. J. Am. Chem. Soc., 2010, 132: 9253-9255.

[403] Jennings PC, Aleksandrov HA, Neyman KM, et al. O₂ dissociation on M@ Pt core–shell particles for 3d, 4d, and 5d Transition Metals. J. Phys. Chem. C, 2015, 119: 11031-11041.

[404] Senkov O, Miracle D Effect of the atomic size distribution on glass forming ability of amorphous metallic alloys. Mater. Res. Bull., 2001, 36: 2183-2198.

[405] Li H, Liao S, You C, et al. Synthesis of three-dimensional Pd nanospheres decorated with a Pt monolayer for the oxygen reduction reaction. Int. J. Hydrog. Energy, 2014, 39: 14018-14026.

[406] Zhang J, Vukmirovic MB, Xu Y, et al. Controlling the catalytic activity of platinum-monolayer electrocatalysts for oxygen reduction with different substrates. Angew. Chem. Int. Ed., 2005, 44: 2132-2135.

[407] Khateeb S, Guerreo S, Su D, et al. Fuel cell performance of palladium − platinum core − shell electrocatalysts synthesized in gram-scale batches. J. Electrochem. Soc., 2016, 163: F708-F713.

[408] Zhang L, Zhu S, Chang Q, et al. Palladium–platinum core–shell electrocatalysts for oxygen reduction reaction prepared with the assistance of citric acid. ACS Catal., 2016, 6: 3428-3432.

[409] Zhang Y, Hsieh YC, Volkov V, et al. High performance Pt monolayer catalysts produced via core-catalyzed coating in ethanol. ACS Catal., 2014, 4: 738-742.

[410] Zhu S, Yue J, Qin X, et al. The role of citric acid in perfecting platinum monolayer on palladium nanoparticles during the surface limited redox replacement reaction. J. Electrochem. Soc., 2016, 163: D3040-D3046.

[411] Wang X, Choi SI, Roling LT, et al. Palladium − platinum core − shell icosahedra with substantially enhanced activity and durability towards oxygen reduction. Nat. Commun., 2015, 6: 7594.

[412] Humbert MP, Smith BH, Wang Q, et al. Synthesis and characterization of palladium–platinum core–shell electrocatalysts for oxygen reduction. Electrocatalysis, 2012, 3: 298-303.

[413] Taufany F, Pan CJ, Lai FJ, et al. Relating the composition of Pt _xRu_100−x/C nanoparticles to their structural aspects and electrocatalytic activities in the methanol oxidation reaction. Chem. Eur. J., 2013, 19: 905-915.

[414] Kakati N, Maiti J, Lee SH, et al. Anode catalysts for direct methanol fuel cells in acidic media: do we have any alternative for Pt or Pt − Ru?. Chem. Rev., 2014, 114: 12397-12429.

[415] Liu P, Nørskov JK Ligand and ensemble effects in adsorption on alloy surfaces. Phys. Chem. Chem. Phys., 2001, 3: 3814-3818.

[416] Zhang L, Kim J, Zhang J, et al. Ti₄O₇ supported Ru@Pt core–shell catalyst for CO-tolerance in PEM fuel cell hydrogen oxidation reaction. Appl. Energy, 2013, 103: 507-513.

[417] Sasaki K, Wang JX, Balasubramanian M, et al. Ultra-low platinum content fuel cell anode electrocatalyst with a long-term performance stability. Electrochim. Acta, 2004, 49: 3873-3877.

[418] Li Y, Zheng L, Liao S, et al. Pt^∧Ru/C catalysts synthesized by a two-stage polyol reduction process for methanol oxidation reaction. J. Power Sources, 2011, 196: 10570-10575.

[419] Muthuswamy N, de la Fuente JLG, Tran DT, et al. Ru@Pt core–shell nanoparticles for methanol fuel cell catalyst: control and effects of shell composition. Int. J. Hydrog. Energy, 2013, 38: 16631-16641.

[420] Wang JJ, Liu YT, Chen IL, et al. Near-monolayer platinum shell on core–shell nanocatalysts for high-performance direct methanol fuel cell. J. Phys. Chem. C, 2014, 118: 2253-2262.

[421] Alayoglu S, Zavalij P, Eichhorn B, et al. Structural and architectural evaluation of bimetallic nanoparticles: a case study of Pt − Ru core − shell and alloy nanoparticles. ACS Nano, 2009, 3: 3127-3137.

[422] Hsieh YC, Chang LC, Wu PW, et al. Displacement reaction of Pt on carbon-supported Ru nanoparticles in hexachloroplatinic acids. Appl. Catal. B, 2011, 103: 116-127.

[423] Chen CH, Sarma LS, Wang DY, et al. Platinum-decorated ruthenium nanoparticles for enhanced methanol electrooxidation. ChemCatChem, 2010, 2: 159-166.

[424] Bokach D, de la Fuente JLG, Tsypkin M, et al. High-temperature electrochemical characterization of Ru core Pt shell fuel cell catalyst. Fuel Cells, 2011, 11: 735-744.

[425] Aiyer HN, Vijayakrishnan V, Subbanna G, et al. Investigations of Pd clusters by the combined use of HREM, STM, high-energy spectroscopies and tunneling conductance measurements. Surf. Sci., 1994, 313: 392-398.

[426] Eberhardt W, Fayet P, Cox D, et al. Photoemission from mass-selected monodispersed Pt clusters. Phys. Rev. Lett., 1990, 64: 780.

[427] Toyoda E, Jinnouchi R, Hatanaka T, et al. The d-band structure of Pt nanoclusters correlated with the catalytic activity for an oxygen reduction reaction. J. Phys. Chem. C, 2011, 115: 21236-21240.

[428] Zhang J, Sasaki K, Sutter E, et al. Stabilization of platinum oxygen-reduction electrocatalysts using gold clusters. Science, 2007, 315: 220-222.

[429] Hartl K, Mayrhofer KJJ, Lopez M, et al. AuPt core–shell nanocatalysts with bulk Pt activity. Electrochem. Commun., 2010, 12: 1487-1489.

[430] Dorjgotov A, Jeon Y, Hwang J, et al. Synthesis of durable small-sized bilayer Au@Pt nanoparticles for high performance PEMFC catalysts. Electrochim. Acta, 2017, 228: 389-397.

[431] Zhang Y, Huang Q, Zou Z, et al. Enhanced durability of Au cluster decorated Pt nanoparticles for the oxygen reduction reaction. J. Phys. Chem. C, 2010, 114: 6860-6868.

[432] Lang H, Maldonado S, Stevenson KJ, et al. Synthesis and characterization of dendrimer templated supported bimetallic Pt–Au nanoparticles. J. Am. Chem. Soc., 2004, 126: 12949-12956.

[433] Rajasekharan T, Seshubai V Charge transfer on the metallic atom-pair bond, and the crystal structures adopted by intermetallic compounds. Acta Crystallogr. A, 2012, 68: 156-165.

[434] Weightman P, Cole R, Brooks N, et al. A new approach to the determination of charge transfer in metal alloys. Nucl. Instrum. Methods Phys. Res., Sect. B, 1995, 97: 472-478.

[435] Petkov V, Wanjala BN, Loukrakpam R, et al. Pt–Au alloying at the nanoscale. Nano Lett., 2012, 12: 4289-4299.

[436] Glatzel P, Singh J, Kvashnina KO, et al. In situ characterization of the 5d density of states of Pt nanoparticles upon adsorption of CO. J. Am. Chem. Soc., 2010, 132: 2555-2557.

[437] Guo S, Fang Y, Dong S, et al. High-efficiency and low-cost hybrid nanomaterial as enhancing electrocatalyst: spongelike Au/Pt core/shell nanomaterial with hollow cavity. J. Phys. Chem. C, 2007, 111: 17104-17109.

[438] Yamauchi Y, Tonegawa A, Komatsu M, et al. Electrochemical synthesis of mesoporous Pt–Au binary alloys with tunable compositions for enhancement of electrochemical performance. J. Am. Chem. Soc., 2012, 134: 5100-5109.

[439] Zhao D, Xu BQ Enhancement of Pt utilization in electrocatalysts by using gold nanoparticles. Angew. Chem. Int. Ed., 2006, 45: 4955-4959.

[440] Tang H, Chen JH, Wang MY, et al. Controlled synthesis of platinum catalysts on Au nanoparticles and their electrocatalytic property for methanol oxidation. Appl. Catal. A, 2004, 275: 43-48.

[441] Zhang S, Shao Y, Yin G, et al. Electrostatic self-assembly of a Pt-around-Au nanocomposite with high activity towards formic acid oxidation. Angew. Chem. Int. Ed., 2010, 49: 2211-2214.

[442] Kristian N, Yan Y, Wang X Highly efficient submonolayer Pt-decorated Au nano-catalysts for formic acid oxidation. Chem. Commun., 2008, 3: 353-355.

[443] Zhang L, Iyyamperumal R, Yancey DF, et al. Design of Pt-shell nanoparticles with alloy cores for the oxygen reduction reaction. ACS Nano, 2013, 7: 9168-9172.

[444] Wang T, Yang R, Ouyang S, et al. Light-induced synthesis of clean-surface PdPt@ Pt core–shell nanoparticles with excellent electrocatalytic activity. RSC Adv., 2015, 5: 48992-48996.

[445] Hirunsit P, Balbuena PB Stability of Pt monolayers on Ir − Co cores with and without a Pd interlayer. J. Phys. Chem. C, 2010, 114: 13055-13060.

[446] Alayoglu S, Eichhorn B Rh − Pt bimetallic catalysts: synthesis, characterization, and catalysis of core − shell, alloy, and monometallic nanoparticles. J. Am. Chem. Soc., 2008, 130: 17479-17486.

[447] Beyhan S, Léger JM, Kadırgan F Understanding the influence of Ni Co, Rh and Pd addition to PtSn/C catalyst for the oxidation of ethanol by in situ Fourier transform infrared spectroscopy. Appl. Catal. B, 2014, 144: 66-74.

[448] Xu ZF, Wang Y Effects of alloyed metal on the catalysis activity of Pt for ethanol partial oxidation: adsorption and dehydrogenation on Pt₃M (M = Pt, Ru, Sn, Re, Rh, and Pd). J. Phys. Chem. C, 2011, 115: 20565-20571.

[449] Zhang Y, Janyasupab M, Liu CW, et al. Three dimensional PtRh alloy porous nanostructures: tuning the atomic composition and controlling the morphology for the application of direct methanol fuel cells. Adv. Funct. Mater., 2012, 22: 2570-2575.

[450] Dhavale VM, Unni SM, Kagalwala HN, et al. Ex-situ dispersion of core–shell nanoparticles of Cu–Pt on an in situ modified carbon surface and their enhanced electrocatalytic activities. Chem. Commun., 2011, 47: 3951-3953.

[451] Froemming NS, Henkelman G Optimizing core–shell genetic algorithm. J. Chem. Phys., 2009, 131: 234103.

[452] Yang Z, Zhang Y, Wang J, et al. First-principles study on the Ni@Pt12 Ih core–shell nanoparticles: a good catalyst for oxygen reduction reaction. Phys. Lett. A, 2011, 375: 3142-3148.

[453] Godínez-Salomón F, Hallen-López M, Solorza-Feria O Enhanced electroactivity for the oxygen reduction on Ni@Pt core–shell nanocatalysts. Int. J. Hydrog. Energy, 2012, 37: 14902-14910.

[454] Wang G, Wu H, Wexler D, et al. Ni@Pt core–shell nanoparticles with enhanced catalytic activity for oxygen reduction reaction. J. Alloys Compd., 2010, 503: L1-L4.

[455] Cantane DA, Oliveira FER, Santos SF, et al. Synthesis of Pt-based hollow nanoparticles using carbon-supported Co@Pt and Ni@Pt core–shell structures as templates: electrocatalytic activity for the oxygen reduction reaction. Appl. Catal. B, 2013, 136–137: 351-360.

[456] Bhlapibul S, Pruksathorn K, Piumsomboon P The effect of the stabilizer on the properties of a synthetic Ni core–Pt shell catalyst for PEM fuel cells. Renew. Energy, 2012, 41: 262-266.

[457] Fu XZ, Liang Y, Chen SP, et al. Pt-rich shell coated Ni nanoparticles as catalysts for methanol electro-oxidation in alkaline media. Catal. Commun., 2009, 10: 1893-1897.

[458] Chen Y, Yang F, Dai Y, et al. Ni@ Pt core–shell nanoparticles: synthesis, structural and electrochemical properties. J. Phys. Chem. C, 2008, 112: 1645-1649.

[459] Ding J, Ji S, Wang H, et al. Nano-engineered intrapores in nanoparticles of PtNi networks for increased oxygen reduction reaction activity. J. Power Sources, 2018, 374: 48-54.

[460] Ramos-Sanchez G, Praserthdam S, Godinez-Salomon F, et al. Challenges of modelling real nanoparticles: Ni@Pt electrocatalysts for the oxygen reduction reaction. Phys. Chem. Chem. Phys., 2015, 17: 28286-28297.

[461] Papadimitriou S, Armyanov S, Valova E, et al. Methanol oxidation at Pt − Cu, Pt − Ni, and Pt − Co electrode coatings prepared by a galvanic replacement process. J. Phys. Chem. C, 2010, 114: 5217-5223.

[462] Chen Y, Shi J, Chen S Small-molecule (CO, H₂) electro-oxidation as an electrochemical tool for characterization of Ni@ Pt/C with different Pt coverages. J. Phys. Chem. C, 2015, 119: 7138-7145.

[463] Duan D, Liu S, Yang C, et al. Electrocatalytic performance of Ni core@Pt shell/C core–shell nanoparticle with the Pt in nanoshell. Int. J. Hydrog. Energy, 2013, 38: 14261-14268.

[464] Yuan Q, Duan D, Ma Y, et al. Performance of nano-nickel core wrapped with Pt crystalline thin film for methanol electro-oxidation. J. Power Sources, 2014, 245: 886-891.

[465] Wang XL, Wang H, Lei ZQ, et al. The performance of carbon-supported platinum-decorated nickel electrocatalyst for ethanol oxidation. Chin. J. Catal., 2011, 32: 1519-1524.

[466] Wang XL, Wang H, Wang RF, et al. Carbon-supported platinum-decorated nickel nanoparticles for enhanced methanol oxidation in acid media. J. Solid State Electrochem., 2012, 16: 1049-1054.

[467] Kang J, Wang R, Wang H, et al. Effect of Ni core structure on the electrocatalytic activity of Pt–Ni/C in methanol oxidation. Materials, 2013, 6: 2689-2700.

[468] Ali S, Khan I, Khan SA, et al. Electrocatalytic performance of Ni@Pt core–shell nanoparticles supported on carbon nanotubes for methanol oxidation reaction. J. Electroanal. Chem., 2017, 795: 17-25.

[469] Lin R, Cao C, Zhao T, et al. Synthesis and application of core–shell Co@Pt/C electrocatalysts for proton exchange membrane fuel cells. J. Power Sources, 2013, 223: 190-198.

[470] Wu H, Wexler D, Wang G, et al. Co core–Pt shell nanoparticles as cathode catalyst for PEM fuel cells. J. Solid State Electrochem., 2011, 16: 1105-1110.

[471] Kettner M, Schneider W, Auer A Computational study of Pt/Co core–shell nanoparticles: segregation, adsorbates and catalyst activity. J. Phys. Chem. C, 2012, 116: 15432-15438.

[472] Beard K, Borrelli D, Cramer AM, et al. Preparation and structural analysis of carbon-supported Co core/Pt shell electrocatalysts using electroless deposition methods. ACS Nano, 2009, 3: 2841-2853.

[473] Ali S, Ahmed R, Sohail M, et al. Co@Pt core–shell nanoparticles supported on carbon nanotubes as promising catalyst for methanol electro-oxidation. J. Ind. Eng. Chem., 2015, 28: 344-350.

[474] Ding J, Ji S, Wang H, et al. Tailoring nanopores within nanoparticles of PtCo networks as catalysts for methanol oxidation reaction. Electrochim. Acta, 2017, 255: 55-62.

[475] Habibi B, Ghaderi S Synthesis, characterization and electrocatalytic activity of Co@Pt nanoparticles supported on carbon-ceramic substrate for fuel cell applications. Int. J. Hydrog. Energy, 2015, 40: 5115-5125.

[476] Yang Z, Zhang Y, Wu R High stability and reactivity of Pt-based core–shell nanoparticles for oxygen reduction reaction. J. Phys. Chem. C, 2012, 116: 13774-13780.

[477] Öberg H, Anniyev T, Vojvodic A, et al. Stability of Pt-modified Cu (111) in the presence of oxygen and its implication on the overall electronic structure. J. Phys. Chem. C, 2013, 117: 16371-16380.

[478] di Paola C, Baletto F Oxygen adsorption on small PtNi nanoalloys. Phys. Chem. Chem. Phys., 2011, 13: 7701-7707.

[479] Stamenkovic V, Mun BS, Mayrhofer KJ, et al. Changing the activity of electrocatalysts for oxygen reduction by tuning the surface electronic structure. Angew. Chem., 2006, 118: 2963-2967.

[480] Bae SJ, Yoo SJ, Lim Y, et al. Facile preparation of carbon-supported PtNi hollow nanoparticles with high electrochemical performance. J. Mater. Chem., 2012, 22: 8820-8825.

[481] Liu Y, Hangarter CM, Bertocci U, et al. Oxygen reduction reaction on electrodeposited Pt_100−xNi _x: influence of alloy composition and dealloying. J. Phys. Chem. C, 2012, 116: 7848-7862.

[482] Wang C, Chi M, Li D, et al. Design and synthesis of bimetallic electrocatalyst with multilayered Pt-skin surfaces. J. Am. Chem. Soc., 2011, 133: 14396-14403.

[483] Stamenkovic VR, Fowler B, Mun BS, et al. Improved oxygen reduction activity on Pt₃Ni (111) via increased surface site availability. Science, 2007, 315: 493-497.

[484] Wang LL, Zhang DF, Guo L Phase-segregated Pt–Ni chain-like nanohybrids with high electrocatalytic activity towards methanol oxidation reaction. Nanoscale, 2014, 6: 4635.

[485] Mintsouli I, Georgieva J, Valova E, et al. Pt–Ni carbon-supported catalysts for methanol oxidation prepared by Ni electroless deposition and its galvanic replacement by Pt. J. Solid State Electrochem., 2013, 17: 435-443.

[486] Hu G, Gracia-Espino E, Sandström R, et al. Atomistic understanding of the origin of high oxygen reduction electrocatalytic activity of cuboctahedral Pt₃Co–Pt core–shell nanoparticles. Catal. Sci. Technol., 2016, 6: 1393-1401.

[487] Duan GW, Zhang J, Xu YM, et al. Synthesis and characterization of Pt₃Co@Pt nanocomposites using banana peel extract as novel surfactants. Synth. React. Inorg. Met. Org. Nano-Met. Chem., 2015, 45: 203-209.

[488] Liu Z, Yu C, Rusakova IA, et al. Synthesis of Pt₃Co alloy nanocatalyst via reverse micelle for oxygen reduction reaction in PEMFCs. Top. Catal., 2008, 49: 241-250.

[489] Wang D, Xin HL, Hovden R, et al. Structurally ordered intermetallic platinum–cobalt core–shell nanoparticles with enhanced activity and stability as oxygen reduction electrocatalysts. Nat. Mater., 2013, 12: 81-87.

[490] Jiang R, Rong C, Chu D Surface coverage of Pt atoms on PtCo nanoparticles and catalytic kinetics for oxygen reduction. Electrochim. Acta, 2011, 56: 2532-2540.

[491] Oezaslan M, Strasser P Activity of dealloyed PtCo₃ and PtCu₃ nanoparticle electrocatalyst for oxygen reduction reaction in polymer electrolyte membrane fuel cell. J. Power Sources, 2011, 196: 5240-5249.

[492] Moseley P, Curtin W Computational design of strain in core–shell nanoparticles for optimizing catalytic activity. Nano Lett., 2015, 15: 4089-4095.

[493] Wang H, Ji S, Wang W, et al. Amorphous Pt@PdCu/CNT catalyst for methanol electrooxidation. S. Afr. J. Chem., 2013, 66: 17-20.

[494] Wang R, Li H, Feng H, et al. Preparation of carbon-supported core@shell PdCu@PtRu nanoparticles for methanol oxidation. J. Power Sources, 2010, 195: 1099-1102.

[495] Wang R, Wang H, Wei B, et al. Carbon supported Pt-shell modified PdCo-core with electrocatalyst for methanol oxidation. Int. J. Hydrog. Energy, 2010, 35: 10081-10086.

[496] Wang H, Wang R, Li H, et al. Facile synthesis of carbon-supported pseudo-core@shell PdCu@Pt nanoparticles for direct methanol fuel cells. Int. J. Hydrog. Energy, 2011, 36: 839-848.

[497] Wang H, Ji S, Wang W, et al. Pt decorated PdFe/C: extremely high electrocatalytic activity for methanol oxidation. Int. J. Electrochem. Sci., 2012, 7: 3390-3398.

[498] Wang R, Zhang Z, Wang H, et al. Pt decorating PdCu/C as highly effective electrocatalysts for methanol oxidation. Electrochem. Commun., 2009, 11: 1089-1091.

[499] Sarkar A, Murugan AV, Manthiram A Pt-encapsulated Pd − Co nanoalloy electrocatalysts for oxygen reduction reaction in fuel cells. Langmuir ACS J. Surf. Colloids, 2009, 26: 2894-2903.

[500] Sasaki K, Kuttiyiel KA, Su D, et al. Platinum monolayer on IrFe core–shell nanoparticle electrocatalysts for the oxygen reduction reaction. Electrocatalysis, 2011, 2: 134-140.

[501] Kuttiyiel KA, Sasaki K, Choi Y, et al. Bimetallic IrNi core platinum monolayer shell electrocatalysts for the oxygen reduction reaction. Energy Environ. Sci., 2012, 5: 5297-5304.

[502] Yang J, Chen X, Yang X, et al. Stabilization and compressive strain effect of AuCu core on Pt shell for oxygen reduction reaction. Energy Environ. Sci., 2012, 5: 8976-8981.

[503] Sasaki K, Kuttiyiel KA, Barrio L, et al. Carbon-supported IrNi core–shell nanoparticles: synthesis, characterization, and catalytic activity. J. Phys. Chem. C, 2011, 115: 9894-9902.

[504] Gong K, Su D, Adzic RR Platinum-monolayer shell on AuNi_0.5Fe nanoparticle core electrocatalyst with high activity and stability for the oxygen reduction reaction. J. Am. Chem. Soc., 2010, 132: 14364-14366.

[505] Levy R, Boudart M Platinum-like behavior of tungsten carbide in surface catalysis. Science, 1973, 181: 547-549.

[506] Antolini E, Gonzalez ER Tungsten-based materials for fuel cell applications. Appl. Catal. B, 2010, 96: 245-266.

[507] Serov A, Kwak C Review of non-platinum anode catalysts for DMFC and PEMFC application. Appl. Catal. B, 2009, 90: 313-320.

[508] Esposito DV, Chen JG Monolayer platinum supported on tungsten carbides as low-cost electrocatalysts: opportunities and limitations. Energy Environ. Sci., 2011, 4: 3900-3912.

[509] Liu N Potential application of tungsten carbides as electrocatalysts III. Reactions of methanol, water, and hydrogen on Pt-modified C/W (111) surfaces. J. Catal., 2003, 215: 254-263.

[510] Weigert EC, Stottlemyer AL, Zellner MB, et al. Tungsten monocarbide as potential replacement of platinum for methanol electrooxidation. J. Phys. Chem. C, 2007, 111: 14617-14620.

[511] Hunt ST, Nimmanwudipong T, Román-Leshkov Y Engineering non-sintered, metal-terminated tungsten carbide nanoparticles for catalysis. Angew. Chem. Int. Ed., 2014, 53: 5131-5136.

[512] Ono S, Kikegawa T, Ohishi Y A high-pressure and high-temperature synthesis of platinum carbide. Solid State Commun., 2005, 133: 55-59.

[513] Yates J, Spikes G, Jones G Platinum–carbide interactions: core–shells for catalytic use. Phys. Chem. Chem. Phys., 2015, 17: 4250-4258.

[514] Liu Y, Kelly TG, Chen JG, et al. Metal carbides as alternative electrocatalyst supports. ACS Catal., 2013, 3: 1184-1194.

[515] Esposito DV, Hunt ST, Kimmel YC, et al. A new class of electrocatalysts for hydrogen production from water electrolysis: metal monolayers supported on low-cost transition metal carbides. J. Am. Chem. Soc., 2012, 134: 3025-3033.

[516] Chen ZY, Ma CA, Chu YQ, et al. WC@ meso-Pt core–shell nanostructures for fuel cells. Chem. Commun., 2013, 49: 11677-11679.

[517] Liu Y, Mustain WE Structural and electrochemical studies of Pt clusters supported on high-surface-area tungsten carbide for oxygen reduction. ACS Catal., 2011, 1: 212-220.

[518] Nørskov JK, Rossmeisl J, Logadottir A, et al. Origin of the overpotential for oxygen reduction at a fuel-cell cathode. J. Phys. Chem. B, 2004, 108: 17886-17892.

[519] Esposito DV, Hunt ST, Stottlemyer AL, et al. Low-cost hydrogen-evolution catalysts based on monolayer platinum on tungsten monocarbide substrates. Angew. Chem. Int. Ed., 2010, 49: 9859-9862.

[520] Mellinger ZJ, Weigert EC, Stottlemyer AL, et al. Enhancing CO tolerance of electrocatalysts: electro-oxidation of CO on WC and Pt-modified WC. Electrochem. Solid-State Lett., 2008, 11: B63-B67.

[521] Ma CA, Liu T, Chen L A computational study of H₂ dissociation and CO adsorption on the PtML/WC (0001) surface. Appl. Surf. Sci., 2010, 256: 7400-7405.

[522] Stottlemyer AL, Weigert EC, Chen JG Tungsten carbides as alternative electrocatalysts: from surface science studies to fuel cell evaluation. Ind. Eng. Chem. Res., 2010, 50: 16-22.

[523] Zellner MB, Chen JG Potential application of tungsten carbides as electrocatalysts: synergistic effect by supporting Pt on C/W (110) for the reactions of methanol, water, and CO. J. Electrochem. Soc., 2005, 152: A1483-A1494.

[524] Jeon MK, Lee KR, Lee WS, et al. Investigation of Pt/WC/C catalyst for methanol electro-oxidation and oxygen electro-reduction. J. Power Sources, 2008, 185: 927-931.

[525] Kimmel YC, Xu X, Yu W, et al. Trends in electrochemical stability of transition metal carbides and their potential use as supports for low-cost electrocatalysts. ACS Catal., 2014, 4: 1558-1562.

[526] Qiu Z, Huang H, Du J, et al. Biotemplated synthesis of bark-structured TiC nanowires as Pt catalyst supports with enhanced electrocatalytic activity and durability for methanol oxidation. J. Mater. Chem. A, 2014, 2: 8003-8008.

[527] Roca-Ayats M, García G, Galante J, et al. TiC, TiCN, and TiN supported Pt electrocatalysts for CO and methanol oxidation in acidic and alkaline media. J. Phys. Chem. C, 2013, 117: 20769-20777.

[528] Sui S, Ma L, Zhai Y TiC supported Pt–Ir electrocatalyst prepared by a plasma process for the oxygen electrode in unitized regenerative fuel cells. J. Power Sources, 2011, 196: 5416-5422.

[529] Ou Y, Cui X, Zhang X, et al. Titanium carbide nanoparticles supported Pt catalysts for methanol electrooxidation in acidic media. J. Power Sources, 2010, 195: 1365-1369.

[530] Gomez T, Florez E, Rodriguez JA, et al. Reactivity of transition metals (Pd, Pt, Cu, Ag, Au) toward molecular hydrogen dissociation: extended surfaces versus particles supported on TiC (001) or small is not always better and large is not always bad. J. Phys. Chem. C, 2011, 115: 11666-11672.

[531] Xia X, Jones G, Sarwar M, et al. A DFT study of Pt layer deposition on catalyst supports of titanium oxide, nitride and carbide. J. Mater. Chem. A, 2015, 3: 24504-24511.

[532] Kimmel YC, Yang L, Kelly TG Theoretical prediction and experimental verification of low loading of platinum on titanium carbide as low-cost and stable electrocatalysts. J. Catal., 2014, 312: 216-220.

[533] Hunt ST, Milina M, Alba-Rubio AC Self-assembly of noble metal monolayers on transition metal carbide nanoparticle catalysts. Science, 2016, 352: 974-978.

[534] Zellner MB, Chen JG Surface science and electrochemical studies of WC and W2C PVD films as potential electrocatalysts. Catal. Today, 2005, 99: 299-307.

[535] Ganesan R, Ham DJ, Lee JS Platinized mesoporous tungsten carbide for electrochemical methanol oxidation. Electrochem. Commun., 2007, 9: 2576-2579.

[536] Wang Y, Song S, Shen PK, et al. Nanochain-structured mesoporous tungsten carbide and its superior electrocatalysis. J. Mater. Chem., 2009, 19: 6149-6153.

[537] Bozzini B, Pietro De Gaudenzi G, Fanigliulo A, et al. Electrochemical oxidation of WC in acidic sulphate solution. Corros. Sci., 2004, 46: 453-469.

[538] Zellner MB, Chen JG Synthesis, characterization and surface reactivity of tungsten carbide (WC) PVD films. Surf. Sci., 2004, 569: 89-98.

[539] Weigert EC, Esposito DV, Chen JG Cyclic voltammetry and X-ray photoelectron spectroscopy studies of electrochemical stability of clean and Pt-modified tungsten and molybdenum carbide (WC and Mo₂C) electrocatalysts. J. Power Sources, 2009, 193: 501-506.

[540] Mazza F, Trassatti S Tungsten, titanium, and tantalum carbides and titanium nitrides as electrodes in redox systems. J. Electrochem. Soc., 1963, 110: 847-849.

[541] Xia D, Liu S, Wang Z, et al. Methanol-tolerant MoN electrocatalyst synthesized through heat treatment of molybdenum tetraphenylporphyrin for four-electron oxygen reduction reaction. J. Power Sources, 2008, 177: 296-302.

[542] Zhong H, Zhang H, Liu G, et al. A novel non-noble electrocatalyst for PEM fuel cell based on molybdenum nitride. Electrochem. Commun., 2006, 8: 707-712.

[543] Miura A, Tague ME, Gregoire JM, et al. Synthesis of Pt − Mo − N thin film and catalytic activity for fuel cells. Chem. Mater., 2010, 22: 3451-3456.

[544] Kuttiyiel KA, Sasaki K, Choi Y, et al. Nitride stabilized PtNi core–shell nanocatalyst for high oxygen reduction activity. Nano Lett., 2012, 12: 6266-6271.

[545] Kuttiyiel KA, Choi Y, Hwang SM, et al. Enhancement of the oxygen reduction on nitride stabilized Pt–M (M = Fe Co, and Ni) core–shell nanoparticle electrocatalysts. Nano Energy, 2015, 13: 442-449.

[546] Ding X, Yin S, An K, et al. FeN stabilized FeN@ Pt core–shell nanostructures for oxygen reduction reaction. J. Mater. Chem. A, 2015, 3: 4462-4469.

[547] Hu J, Kuttiyiel KA, Sasaki K, et al. Pt monolayer shell on nitrided alloy core: a path to highly stable oxygen reduction catalyst. Catalysts, 2015, 5: 1321-1332.

[548] Tian X, Tang H, Luo J, et al. High-performance core–shell catalyst with nitride nanoparticles as a core: well-defined titanium copper nitride coated with an atomic Pt layer for the oxygen reduction reaction. ACS Catal., 2017, 7: 3810-3817.

[549] Garg A, Milina M, Ball M, et al. Transition-metal nitride core@noble-metal shell nanoparticles as highly CO tolerant catalysts. Angew. Chem. Int. Ed. Engl., 2017, 56: 8828-8833.

[550] Gasteiger HA, Markovic N, Ross PN, et al. Methanol electrooxidation on well-characterized platinum–ruthenium bulk alloys. J. Phys. Chem., 1993, 97: 12020-12029.

[551] Zhao H, Li L, Yang J, et al. Co@Pt–Ru core–shell nanoparticles supported on multiwalled carbon nanotube for methanol oxidation. Electrochem. Commun., 2008, 10: 1527-1529.

[552] Wang W, Wang R, Wang H, et al. An advantageous method for methanol oxidation: design and fabrication of a nanoporous PtRuNi trimetallic electrocatalyst. J. Power Sources, 2011, 196: 9346-9351.

[553] Wu YN, Liao SJ, Guo HF, et al. High-performance Pd@PtRu/C catalyst for the anodic oxidation of methanol prepared by decorating Pd/C with a PtRu shell. J. Power Sources, 2013, 224: 66-71.

[554] Mao X, Yang L, Yang J, et al. A volcano curve: optimizing activity of shell–core Pt _xRu_y@PdCu/C catalysts for methanol oxidation by tuning Pt/Ru ratio. J. Electrochem. Soc., 2013, 160: H219-H223.

[555] Yang J, Cheng CH, Zhou W, et al. Methanol-tolerant heterogeneous PdCo@PdPt/C electrocatalyst for the oxygen reduction reaction. Fuel Cells, 2010, 10: 907-913.

[556] Gao H, Liao S, Liang Z, et al. Anodic oxidation of ethanol on core–shell structured Ru@PtPd/C catalyst in alkaline media. J. Power Sources, 2011, 196: 6138-6143.

[557] Gao H, Liao S, Zeng J, et al. Preparation and characterization of core–shell structured catalysts using Pt _xPd _y as active shell and nano-sized Ru as core for potential direct formic acid fuel cell application. Electrochim. Acta, 2011, 56: 2024-2030.

[558] Gatalo M, Jovanovič P, Polymeros G, et al. Positive effect of surface doping with Au on the stability of Pt-based electrocatalysts. ACS Catal., 2016, 6: 1630-1634.

[559] Liu S, Wang Y, Liu L, et al. One-pot synthesis of Pd@PtNi core–shell nanoflowers supported on the multi-walled carbon nanotubes with boosting activity toward oxygen reduction in alkaline electrolyte. J. Power Sources, 2017, 365: 26-33.

[560] Bu L, Shao Q, Bin E, et al. PtPb/PtNi intermetallic core/atomic layer shell octahedra for efficient oxygen reduction electrocatalysis. J. Am. Chem. Soc., 2017, 139: 9576-9582.

[561] Zhang N, Feng Y, Zhu X, et al. Superior bifunctional liquid fuel oxidation and oxygen reduction electrocatalysis enabled by PtNiPd core–shell nanowires. Adv. Mater., 2017, 29: 1603774.

[562] Wang KC, Huang HC, Wang CH Synthesis of Pd@Pt₃Co/C core–shell structure as catalyst for oxygen reduction reaction in proton exchange membrane fuel cell. Int. J. Hydrog. Energy, 2017, 42: 11771-11778.

[563] Sun X, Li D, Guo S, et al. Controlling core/shell Au/FePt nanoparticle electrocatalysis via changing the core size and shell thickness. Nanoscale, 2016, 8: 2626-2631.

[564] Jing S, Guo X, Tan Y Branched Pd and Pd-based trimetallic nanocrystals with highly open structures for methanol electrooxidation. J. Mater. Chem. A, 2016, 4: 7950-7961.

[565] Li Y, Chen L, Chen K, et al. Monodisperse PdCu@PtCu core@shell nanocrystal and their high activity and durability for oxygen reduction reaction. Electrochim. Acta, 2016, 192: 227-233.

[566] Wang Q, Zhao Z, Jia Y, et al. Unique Cu@CuPt core–shell concave octahedron with enhanced methanol oxidation activity. ACS Appl. Mater. Interfaces., 2017, 9: 36817-36827.

[567] Greeley J, Nørskov JK, Mavrikakis M Electronic structure and catalysis on metal surfaces. Annu. Rev. Phys. Chem., 2002, 53: 319-348.

[568] Hammer B, Norskov J Advances in Catalysis 2000 San Diego Academic Press Inc. 71 129

[569] Greeley J, Stephens I, Bondarenko A, et al. Alloys of platinum and early transition metals as oxygen reduction electrocatalysts. Nat. Chem., 2009, 1: 552-556.

[570] Wu J, Li P, Pan YTF, et al. Surface lattice-engineered bimetallic nanoparticles and their catalytic properties. Chem. Soc. Rev., 2012, 41: 8066-8074.

[571] Nørskov JK, Bligaard T, Rossmeisl J, et al. Towards the computational design of solid catalysts. Nat. Chem., 2009, 1: 37-46.

[572] Hammer B, Nørskov JK Theoretical surface science and catalysis: calculations and concepts. Adv. Catal., 2000, 45: 71-129.

[573] Hammer B, Hansen LB, Nørskov JK Improved adsorption energetics within density-functional theory using revised Perdew–Burke–Ernzerhof functionals. Phys. Rev. B, 1999, 59: 7413.

[574] Mavrikakis M, Hammer B, Nørskov JK Effect of strain on the reactivity of metal surfaces. Phys. Rev. Lett., 1998, 81: 2819.

[575] Karlberg G Adsorption trends for water, hydroxyl, oxygen, and hydrogen on transition-metal and platinum-skin surfaces. Phys. Rev. B, 2006, 74: 153414.

[576] Mukerjee S, Srinivasan S, Soriaga MP, et al. Effect of preparation conditions of Pt alloys on their electronic, structural, and electrocatalytic activities for oxygen reduction-XRD, XAS, and electrochemical studies. J. Phys. Chem., 1995, 99: 4577-4589.

[577] Kitchin JR, Nørskov JK, Barteau MA, et al. Role of strain and ligand effects in the modification of the electronic and chemical properties of bimetallic surfaces. Phys. Rev. Lett., 2004, 93: 156801.

[578] Gawande MB Core–shell nanoparticles: synthesis and applications in catalysis and electrocatalysis. Chem. Soc. Rev., 2015, 44: 7540-7590.

[579] Kitchin J, Nørskov JK, Barteau M, et al. Modification of the surface electronic and chemical properties of Pt (111) by subsurface 3d transition metals. J. Chem. Phys., 2004, 120: 10240-10246.

[580] Wang X, Orikasa Y, Takesue Y, et al. Quantitating the lattice strain dependence of monolayer Pt shell activity toward oxygen reduction. J. Am. Chem. Soc., 2013, 135: 5938-5941.

[581] Xiong Y, Shan H, Zhou Z, et al. Tuning surface structure and strain in Pd–Pt core–shell nanocrystals for enhanced electrocatalytic oxygen reduction. Small, 2017, 13: 1603423.

[582] Gan L, Yu R, Luo J, et al. Lattice strain distributions in individual dealloyed Pt–Fe catalyst nanoparticles. J. Phys. Chem. Lett., 2012, 3: 934-938.

[583] Rodriguez J, Goodman DW The nature of the metal-metal bond in bimetallic surfaces. Science, 1992, 257: 897-903.

[584] Schlapka A, Lischka M, Gross A, et al. Surface strain versus substrate interaction in heteroepitaxial metal layers: Pt on Ru (0001). Phys. Rev. Lett., 2003, 91: 016101.

[585] Yang J, Zhou W, Cheng CH, et al. Pt-decorated PdFe nanoparticles as methanol-tolerant oxygen reduction electrocatalyst. ACS Appl. Mater. Interfaces., 2009, 2: 119-126.

[586] Stephens IE, Bondarenko AS, Perez-Alonso FJ, et al. Tuning the activity of Pt (111) for oxygen electroreduction by subsurface alloying. J. Am. Chem. Soc., 2011, 133: 5485-5491.

[587] Gauthier Y, Schmid M, Padovani S, et al. Adsorption sites and ligand effect for CO on an alloy surface: a direct view. Phys. Rev. Lett., 2001, 87: 036103.

[588] Jennings PC, Pollet BG, Johnston RL Electronic properties of Pt–Ti nanoalloys and the effect on reactivity for use in PEMFCs. J. Phys. Chem. C, 2012, 116: 15241-15250.

[589] Chang SH, Su WN, Yeh MH, et al. Structural and electronic effects of carbon-supported Pt _xPd_1−x nanoparticles on the electrocatalytic activity of the oxygen-reduction reaction and on methanol tolerance. Chem. Eur. J., 2010, 16: 11064-11071.

[590] Ma Y, Balbuena PB Surface adsorption and stabilization effect of iridium in Pt-based alloy catalysts for PEM fuel cell cathodes. ECS Trans., 2009, 25: 1037-1044.

[591] Koper MT, Shubina TE, van Santen RA Periodic density functional study of CO and OH adsorption on Pt–Ru alloy surfaces: implications for CO tolerant fuel cell catalysts. J. Phys. Chem. B, 2002, 106: 686-692.

[592] de Mongeot FB, Scherer M, Gleich B, et al. CO adsorption and oxidation on bimetallic Pt/Ru (0001) surfaces: a combined STM and TPD/TPR study. Surf. Sci., 1998, 411: 249-262.

[593] Brankovic S, Marinkovic N, Wang J, et al. Carbon monoxide oxidation on bare and Pt-modified Ru (1010) and Ru (0001) single crystal electrodes. J. Electroanal. Chem., 2002, 532: 57-66.

[594] Del Popolo M, Leiva E, Mariscal M, et al. On the generation of metal clusters with the electrochemical scanning tunneling microscope. Surf. Sci., 2005, 597: 133-155.

[595] Gorzkowski MT, Lewera A Probing the limits of d-band center theory: electronic and electrocatalytic properties of Pd-shell–Pt-core nanoparticles. J. Phys. Chem. C, 2015, 119: 18389-18395.

[596] Wang X, Orikasa Y, Uchimoto Y Platinum-based electrocatalysts for the oxygen-reduction reaction: determining the role of pure electronic charge transfer in electrocatalysis. ACS Catal., 2016, 6: 4195-4198.

[597] Kaito T, Mitsumoto H, Sugawara S, et al. K-edge X-ray absorption fine structure analysis of Pt/Au core–shell electrocatalyst: evidence for short Pt–Pt distance. J. Phys. Chem. C, 2014, 118: 8481-8490.

[598] Lai FJ, Su WN, Sarma LS, et al. Chemical dealloying mechanism of bimetallic Pt–Co nanoparticles and enhancement of catalytic activity toward oxygen reduction. Chem. Eur. J., 2010, 16: 4602-4611.

[599] Sachtler J, Somorjai G Influence of ensemble size on CO chemisorption and catalytic n-hexane conversion by Au–Pt (111) bimetallic single-crystal surfaces. J. Catal., 1983, 81: 77-94.

[600] Lin SP, Wang KW, Liu CW, et al. Trends of oxygen reduction reaction on platinum alloys: a computational and experimental study. J. Phys. Chem. C, 2015, 119: 15224-15231.

[601] Zhong W, Qi Y, Deng M The ensemble effect of formic acid oxidation on platinum–gold electrode studied by first-principles calculations. J. Power Sources, 2015, 278: 203-212.

[602] Han Y, Ouyang Y, Xie Z, et al. Controlled growth of Pt–Au alloy nanowires and their performance for formic acid electrooxidation. J. Mater. Sci. Technol., 2016, 32: 639-645.

[603] Duan T, Zhang R, Ling L, et al. Insights into the effect of Pt atomic ensemble on HCOOH oxidation over Pt-decorated Au bimetallic catalyst to maximize Pt utilization. J. Phys. Chem. C, 2016, 120: 2234-2246.