Tuning the Activity of Pt(111) for Oxygen Electroreduction by Subsurface Alloying
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- 作者：Ifan E. L. Stephens ; Alexander S. Bondarenko ; Francisco J. Perez-Alonso ; Federico Calle-Vallejo ; Lone Bech ; Tobias P. Johansson ; Anders K. Jepsen ; Rasmus Frydendal ; Brian P. Knudsen ; Jan Rossmeisl ; Ib Chorkendorff
- 刊名：Journal of the American Chemical Society
- 出版年：2011
- 出版时间：April 13, 2011
- 年：2011
- 卷：133
- 期：14
- 页码：5485-5491
- 全文大小：972K
- 年卷期：v.133,no.14(April 13, 2011)
- ISSN：1520-5126
文摘
To enable the development of low temperature fuel cells, significant improvements are required to the efficiency of the Pt electrocatalysts at the cathode, where oxygen reduction takes place. Herein, we study the effect of subsurface solute metals on the reactivity of Pt, using a Cu/Pt(111) near-surface alloy. Our investigations incorporate electrochemical measurements, ultrahigh vacuum experiments, and density functional theory. Changes to the OH binding energy, 螖EOH, were monitored in situ and adjusted continuously through the subsurface Cu coverage. The incorporation of submonolayer quantities of Cu into Pt(111) resulted in an 8-fold improvement in oxygen reduction activity. The most optimal catalyst for oxygen reduction has an 螖EOH 鈮?0.1 eV weaker than that of pure Pt, validating earlier theoretical predictions.