Your browser doesn't support javascript.
loading
Introducing Electron Buffers into Intermetallic Pt Alloys against Surface Polarization for High-Performing Fuel Cells.
Liu, Xuan; Wang, Yuhan; Liang, Jiashun; Li, Shenzhou; Zhang, Siyang; Su, Dong; Cai, Zhao; Huang, Yunhui; Elbaz, Lior; Li, Qing.
Afiliación
  • Liu X; State Key Laboratory of Material Processing and Die & Mould Technology, School of Materials Science and Engineering, Huazhong University of Science and Technology, Wuhan 430074, China.
  • Wang Y; National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China.
  • Liang J; State Key Laboratory of Material Processing and Die & Mould Technology, School of Materials Science and Engineering, Huazhong University of Science and Technology, Wuhan 430074, China.
  • Li S; State Key Laboratory of Material Processing and Die & Mould Technology, School of Materials Science and Engineering, Huazhong University of Science and Technology, Wuhan 430074, China.
  • Zhang S; State Key Laboratory of Material Processing and Die & Mould Technology, School of Materials Science and Engineering, Huazhong University of Science and Technology, Wuhan 430074, China.
  • Su D; National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China.
  • Cai Z; Faculty of Materials Science and Chemistry, China University of Geosciences (Wuhan), Wuhan, Hubei 430074, China.
  • Huang Y; State Key Laboratory of Material Processing and Die & Mould Technology, School of Materials Science and Engineering, Huazhong University of Science and Technology, Wuhan 430074, China.
  • Elbaz L; Department of Chemistry and the Bar-Ilan Institute of Nanotechnology and Advanced Materials, Bar-Ilan University, Ramat-Gan 5290002, Israel.
  • Li Q; State Key Laboratory of Material Processing and Die & Mould Technology, School of Materials Science and Engineering, Huazhong University of Science and Technology, Wuhan 430074, China.
J Am Chem Soc ; 146(3): 2033-2042, 2024 Jan 24.
Article en En | MEDLINE | ID: mdl-38206169
ABSTRACT
Surface polarization under harsh electrochemical environments usually puts catalysts in a thermodynamically unstable state, which strictly hampers the thermodynamic stability of Pt-based catalysts in high-performance fuel cells. Here, we report a strategy by introducing electron buffers (variable-valence metals, M = Ti, V, Cr, and Nb) into intermetallic Pt alloy nanoparticle catalysts to suppress the surface polarization of Pt shells using the structurally ordered L10-M-PtFe as a proof of concept. Operando X-ray absorption spectra analysis suggests that with the potential increase, electron buffers, especially Cr, could facilitate an electron flow to form a electron-enriched Pt shell and thus weaken the surface polarization and tensile Pt strain. The best-performing L10-Cr-PtFe/C catalyst delivers superb oxygen reduction reaction (ORR) activity (mass activity = 1.41/1.02 A mgPt-1 at 0.9 V, rated power density = 14.0/9.2 W mgPt-1 in H2-air under a total Pt loading of 0.075/0.125 mgPt cm-2, respectively) and stability (20 mV voltage loss at 0.8 A cm-2 after 60,000 cycles of accelerated durability test) in a fuel cell cathode, representing one of the best reported ORR catalysts. Density functional theory calculations reveal that the optimized surface strain by introducing Cr on L10-PtFe/C accounts for the enhanced ORR activity, and the durability enhancement stems from the charge transfer contribution of Cr to the Pt shells and the increased kinetic energy barrier for Pt dissolution/Fe diffusion.

Texto completo: 1 Bases de datos: MEDLINE Idioma: En Revista: J Am Chem Soc Año: 2024 Tipo del documento: Article País de afiliación: China

Texto completo: 1 Bases de datos: MEDLINE Idioma: En Revista: J Am Chem Soc Año: 2024 Tipo del documento: Article País de afiliación: China