Highly Active, CO-Tolerant, and Robust Hydrogen Anode Catalysts: Pt–M (M = Fe, Co, Ni) Alloys with Stabilized Pt-Skin Layers

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• 作者：Guoyu Shi ; Hiroshi Yano ; Donald A. Tryk ; Akihiro Iiyama ; Hiroyuki Uchida
• 刊名：ACS Catalysis
• 出版年：2017
• 出版时间：January 6, 2017
• 年：2017
• 卷：7
• 期：1
• 页码：267-274
• 全文大小：484K
• ISSN：2155-5435

文摘

The electrocatalytic activity for the hydrogen oxidation reaction (HOR) in the presence of 1000 ppm of CO has been investigated on a series of binary Pt alloy catalysts Pt–M (M = Fe, Co, Ni), having two atomic layers of stabilized Pt skin (Pt_2AL), supported on carbon black (Pt_2AL–PtFe/C, Pt_2AL–PtCo/C, and Pt_2AL–PtNi/C) in 0.1 M HClO₄ solution at 70 and 90 °C. It was found that Pt_2AL–PtFe/C exhibited the highest CO-tolerant HOR activity (with respect to the area-specific activity j_s and the mass activity MA), followed by Pt_2AL–PtCo/C and Pt_2AL–PtNi/C. Such an order of the j_s values for the HOR with and without adsorbed CO can be correlated with density functional theory calculations, which have enabled us to propose a mechanism for the HOR on these surfaces. The apparent values of MA for the HOR on Pt_2AL–PtFe/C at 20 mV vs RHE were 2–3 times larger than those for the conventional commercial catalyst c-Pt₂Ru₃/C over the whole CO coverage range from 0 to 0.7 at 70 and 90 °C. For an accelerated durability test simulating air exposure (2500 potential cycles between 0.02 and 0.95 V), the apparent j_s values for the CO-tolerant HOR on these Pt-skin catalysts were maintained completely, indicating that the dealloying of M components was virtually suppressed, whereas a significant reduction in j_s was observed for c-Pt₂Ru₃/C. A great mitigation of the particle agglomeration was also a highly attractive property of our catalysts in comparison with the commercial catalysts c-Pt/C and c-Pt₂Ru₃/C.