Positive Effect of Surface Doping with Au on the Stability of Pt-Based Electrocatalysts

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• 作者：Matija Gatalo ; Primož Jovanovič ; George Polymeros ; Jan-Philipp Grote ; Andraž Pavlišič ; Francisco Ruiz- Zepeda ; Vid Simon Šelih ; Martin Šala ; Samo Hočevar ; Marjan Bele ; Karl J.J. Mayrhofer ; Nejc Hodnik ; Miran Gaberšček
• 刊名：ACS Catalysis
• 出版年：2016
• 出版时间：March 4, 2016
• 年：2016
• 卷：6
• 期：3
• 页码：1630-1634
• 全文大小：315K
• ISSN：2155-5435

文摘

Corrosion resistance of a transition-metal-rich PtCu₃/C oxygen reduction reaction (ORR) catalyst as a representative of Pt alloy-based materials has been significantly improved by doping with small amounts of gold (<1 at. %). Transmission electron microscopy imaging shows near-surface segregation of both platinum and gold with the underlying core consisting predominantly of intermetallic PtCu₃. The resulting PtAu skin catalyst shows improved resistance against Cu dissolution, as well as against carbon corrosion if compared to its PtCu₃ precursor. Also, it exhibits a much higher Pt and carbon stability than a widely used Pt/C standard. Most importantly, the Au-doped sample shows a substantial improvement in stability at the elevated temperature (60 °C) degradation test (10 000 cycles; 0.4–1.2 V_RHE) simulating a real PEM fuel cell environment.