Unprecedented Dependence of the Oxygen Reduction Activity on Co Content at Pt Skin/Pt-Co(111) Single Crystal Electrodes
Unprecedented Dependence of the Oxygen Reduction Activity on Co Content at Pt Skin/Pt-Co(111) Single Crystal Electrodes
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Pt Skin/Pt-Co(111) 单晶电极中氧还原活性对 Co 含量的前所未有的依赖性
DOI：
10.1016/j.elecom.2016.03.015
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发表时间：
2016
影响因子：
5.4
通讯作者：
A. Iiyama and H. Uchida
中科院分区：
文献类型：
--
作者：
M. Wakisaka;S. Kobayashi;S. Morishima;Y. Hyuga;D. A. Tryk;M. Watanabe;A. Iiyama and H. Uchida
采用旋转圆盘电极法，在定义良好的Pt-skin/Pt100−xCox（111）单晶电极上评价了氧还原反应（ORR）的动力学控制区域比活性jk与Co含量的关系。在纯h2o2气氛下退火形成的pt皮层被澄清为由原子平坦的梯田组成，其原子排列与底层晶体相同。在25个原子%-Co下，jkvalue在0.9 V时达到最大值3.0 mA cm−2，是纯Pt（111）的约25倍。Pt-skin/ Pt-Co（111）电极的ORR活性增强不能用OH中毒减少来解释，因为在n2净化溶液中，在0.9 V下测量的表面氧化电荷密度几乎是恒定的。
The kinetically controlled area-specific activities,jk, for the oxygen reduction reaction (ORR) were evaluated at well-defined Pt-skin/Pt100 −xCox(111) single crystal electrodes as a function of Co content by use of the rotating disk electrode method. The Pt-skin layer formed by annealing under a pure H2atmosphere was clarified to consist of atomically flat terraces with the same atomic arrangement as the underlying crystal. At 25 atom%-Co, thejkvalue reached a maximum as high as 3.0 mA cm− 2at 0.9 V vs. RHE, which is ca. 25 times larger than that on pure Pt(111). Such an enhanced ORR activity of Pt-skin/Pt–Co(111) electrodes cannot be explained on the basis of decreased OH poisoning, because the surface oxidation charge densities measured at 0.9 V in N2-purged solution were nearly constant.