High-Loading Intermetallic Pt<sub>3</sub>Co/C Core–Shell Nanoparticles as Enhanced Activity Electrocatalysts toward the Oxygen Reduction Reaction (ORR)

Xiong, Yin; Xiao, Li; Yang, Yao; DiSalvo, Francis J.; Abruña, Héctor D.

doi:10.1021/acs.chemmater.7b04201

Cited by 146 publications

(108 citation statements)

References 44 publications

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“…The ECSA of the Au@PtCoAu/C catalyst was higher than that of the Pt 4 Co/C, indicating a better Pt utilization in the Au@PtCoAu/C catalysts. [ 33–34 ] It could be also observed that the ECSA of the Au@Co@PtCoAu/C catalyst was relatively smaller than the Au@PtCoAu/C catalyst. In previous reports, the segregation of Au to the surface layer was used to explain the decreased ECSA for some samples with Au cores.…”

Section: Resultsmentioning

confidence: 99%

Structure Design Reveals the Role of Au for ORR Catalytic Performance Optimization in PtCo‐Based Catalysts

Guo

Zhang

2020

Adv Funct Materials

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Au-incorporation is a promising strategy to retard composition-loss in Pt-based catalyst. However, the unclear mechanism limits guided catalyst design and the performance optimization. Here, direct evidence is provided to validate the outward diffusion of Au atoms in Au-core/Ptbased-shell structures. A Co interlayer is built between the Au-core and PtCo-based shell to exclude the possibility of atomic diffusion caused by interfacial alloying. In conjunction with the improved catalytic durability of the Au-core@Pt-based-shell structure, it is reasonable to conclude that it is the subsurface segregated Au atoms rather than interfacial interaction that boosts the catalytic durability of Au-core/Pt-based-shell structured catalysts towards oxygen reduction reaction. More importantly, by constructing Au-core@Co-interlayer@PtCoAu-shell multilayer structure, the specific (1.730 mA cm −2 ) and mass (0.692 A mg −1 Pt ) activities are enhanced 7-and 4-fold relative to the commercial Pt/C. After 10 000 cycles of accelerated durability test, the mass activity loss for the multilayered catalyst is as low as 6.14% while the loss exceeds 35% for the commercial Pt/C catalyst. The improved catalytic performance of the Au@Co@PtCoAu multilayer structure can be ascribed to the finely modulated electronic structure and the compensated composition loss owing to the delicate structure and composition profile design.

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Section: Resultsmentioning

confidence: 99%

Structure Design Reveals the Role of Au for ORR Catalytic Performance Optimization in PtCo‐Based Catalysts

Guo

Zhang

2020

Adv Funct Materials

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“…The strategies to minimize the Pt amount call for a shift from monometallic nanoparticles (NPs) to the use of nano-engineered architectures with tailored morphologies and compositions [ 1 , 2 ]. For instance, bi- or tri-metallic particles, alloys [ 3 , 4 , 5 , 6 ] and successively de-alloyed [ 7 ] structures where Pt is associated with other transition metals (e.g., Ni, Co, Cu) have been prepared and demonstrated high ORR activity and durability. Another very promising class of tailored electrocatalysts is represented by core@shell nanostructures with a thin Pt skin covering a transition metal core in 0D (particle-like) [ 8 , 9 , 10 ] and 1D (fiber-like) morphologies [ 11 , 12 , 13 , 14 , 15 , 16 , 17 ].…”

Section: Introductionmentioning

confidence: 99%

Electrodeposition of Two-Dimensional Pt Nanostructures on Highly Oriented Pyrolytic Graphite (HOPG): The Effect of Evolved Hydrogen and Chloride Ions

et al. 2018

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We discuss the electrodeposition of two-dimensional (2D) Pt-nanostructures on Highly Oriented Pyrolytic Graphite (HOPG) achieved under constant applied potential versus a Pt counter electrode (Eappl = ca. −2.2 V vs. NHE, normal hydrogen electrode). The deposition conditions are discussed in terms of the electrochemical behavior of the electrodeposition precursor (H2PtCl6). We performed cyclic voltammetry (CV) of the electrochemical Pt deposit on HOPG and on Pt substrates to study the relevant phenomena that affect the morphology of Pt deposition. Under conditions where the Pt deposition occurs and H2 evolution is occurring at the diffusion-limited rate (−0.3 V vs. NHE), Pt forms larger structures on the surface of HOPG, and the electrodeposition of Pt is not limited by diffusion. This indicates the need for large overpotentials to direct the 2D growth of Pt. Investigation of the possible effect of Cl− showed that Cl− deposits on the surface of Pt at low overpotentials, but strips from the surface at potentials more positive than the electrodeposition potential. The CV of Pt on HOPG is a strong function of the nature of the surface. We propose that during immersion of HOPG in the electrodeposition solution (3 mM H2PtCl6, 0.5 M NaCl, pH 2.3) Pt islands are formed spontaneously, and these islands drive the growth of the 2D nanostructures. The reducing agents for the spontaneous deposition of Pt from solution are proposed as step edges that get oxidized in the solution. We discuss the possible oxidation reactions for the edge sites.

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“…14 [351,352]. And through surface segregation, numerous core-shell-structured electrocatalysts, such as Pd@Pt, Ru@Pt, Au@Pt, Cu@Pt, Fe@ Pt, Co@Pt, and Ni@Pt have been synthesized [353][354][355][356][357][358][359].…”

Section: Principles and Development Of Surface Segregationmentioning

confidence: 99%

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

Wang

Luo

et al. 2018

Electrochem. Energ. Rev.

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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; singlenon-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.

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High-Loading Intermetallic Pt₃Co/C Core–Shell Nanoparticles as Enhanced Activity Electrocatalysts toward the Oxygen Reduction Reaction (ORR)

Cited by 146 publications

References 44 publications

Structure Design Reveals the Role of Au for ORR Catalytic Performance Optimization in PtCo‐Based Catalysts

Structure Design Reveals the Role of Au for ORR Catalytic Performance Optimization in PtCo‐Based Catalysts

Electrodeposition of Two-Dimensional Pt Nanostructures on Highly Oriented Pyrolytic Graphite (HOPG): The Effect of Evolved Hydrogen and Chloride Ions

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

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High-Loading Intermetallic Pt3Co/C Core–Shell Nanoparticles as Enhanced Activity Electrocatalysts toward the Oxygen Reduction Reaction (ORR)

Cited by 146 publications

References 44 publications

Structure Design Reveals the Role of Au for ORR Catalytic Performance Optimization in PtCo‐Based Catalysts

Structure Design Reveals the Role of Au for ORR Catalytic Performance Optimization in PtCo‐Based Catalysts

Electrodeposition of Two-Dimensional Pt Nanostructures on Highly Oriented Pyrolytic Graphite (HOPG): The Effect of Evolved Hydrogen and Chloride Ions

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

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High-Loading Intermetallic Pt₃Co/C Core–Shell Nanoparticles as Enhanced Activity Electrocatalysts toward the Oxygen Reduction Reaction (ORR)