Operando Time-Resolved X-ray Absorption Fine Structure Study for Surface Events on a Pt3Co/C Cathode Catalyst in a Polymer Electrolyte Fuel Cell during Voltage-Operating Processes

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• 作者：Nozomu Ishiguro ; Takahiro Saida ; Tomoya Uruga ; Shin-ichi Nagamatsu ; Oki Sekizawa ; Kiyofumi Nitta ; Takashi Yamamoto ; Shin-ichi Ohkoshi ; Yasuhiro Iwasawa ; Toshihiko Yokoyama ; Mizuki Tada
• 刊名：ACS Catalysis
• 出版年：2012
• 出版时间：July 6, 2012
• 年：2012
• 卷：2
• 期：7
• 页码：1319-1330
• 全文大小：631K
• 年卷期：v.2,no.7(July 6, 2012)
• ISSN：2155-5435

文摘

The structural kinetics of surface events on a Pt₃Co/C cathode catalyst in a polymer electrolyte fuel cell (PEFC) was investigated by operando time-resolved X-ray absorption fine structure (XAFS) with a time resolution of 500 ms. The rate constants of electrochemical reactions, the changes in charge density on Pt, and the changes in the local coordination structures of the Pt₃Co alloy catalyst in the PEFC were successfully evaluated during fuel-cell voltage-operating processes. Significant time lags were observed between the electrochemical reactions and the structural changes in the Pt₃Co alloy catalyst. The rate constants of all the surface events on the Pt₃Co/C catalyst were significantly higher than those on the Pt/C catalyst, suggesting the advantageous behaviors (cell performance and catalyst durability) on the Pt₃Co alloy cathode catalyst.

Keywords:

fuel cell; PEFC; operando XAFS; time-resolved XAFS; Pt₃Co catalyst; structural kinetics