Mechanism of CO Tolerance at Pt-Alloy Anode Catalysts for Polymer Electrolyte Fuel Cells

• WATANABE Masahiro

  Laboratory of Electrochemical Energy Conversion, Faculty of Engineering, Yamanashi University

• ZHU Yimin

  Laboratory of Electrochemical Energy Conversion, Faculty of Engineering, Yamanashi University

• IGARASHI Hiroshi

  Laboratory of Electrochemical Energy Conversion, Faculty of Engineering, Yamanashi University

• UCHIDA Hiroyuki

  Laboratory of Electrochemical Energy Conversion, Faculty of Engineering, Yamanashi University

抄録

We have found an excellent CO tolerance at Pt anodes alloyed with the second metals in spite of the formation of Pt skin layer (ca. 1-2 nm in thickness) over the alloy surfaces due to the dissolution of the second metals and proposed a new mechanism for the catalysis. In this study, ATR-SEIRAS, coupled with CV measurement, was used to observe the oxidation process of adsorbed CO on the typical Pt-Fe alloy. The alloy anode exhibits a lower saturated coverage with CO than that of pure Pt. Linear CO is observed predominantly on the alloy electrode, differing from both of linear and bridged CO besides COOH on the pure Pt. The negative-shift of the wavenumber for the linear CO stretching and the broadening of the half-wave width at the alloy also indicate the weakening of metal-CO bonding and the increased mobility of the adsorbed CO, respectively. As a presumable effect of the electronic structure change at the Pt skin, the dissociation/oxidation of adsorbed water as well as a formation of adsorbed HOOH species are clearly observed beyond 0.6 V in the electrolyte solution without CO. The mechanism of CO tolerance at the Pt skin on top of the alloy surface with an increased d-band vacancy, proposed previously by us, is supported by the present SEIRAS data as the “detoxification mechanism”, featured by an increased mobility of the adsorbed CO with suppressed coverage.

収録刊行物

• Electrochemistry

  Electrochemistry 68 (4), 244-251, 2000-04-05

  公益社団法人　電気化学会

キーワード

• Fuel Cell
• CO Tolerance
• Pt Alloy Electrocatalysis
• FTIR

詳細情報

• CRID: 1390282752367947392
• NII論文ID: 10004455181
• NII書誌ID: AN00151637
• DOI: 10.5796/electrochemistry.68.244
• ISSN: 21862451
• ISSN: 13443542
• NDL書誌ID: 5358544
• Web Site: https://ndlsearch.ndl.go.jp/books/R000000004-I5358544
• Web Site: https://www.jstage.jst.go.jp/article/electrochemistry/68/4/68_244/_pdf
• 本文言語コード: en
• データソース種別:
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• 抄録ライセンスフラグ: 使用可