In situ video STM studies of the hydrogen-induced reconstruction of Cu(100): potential and pH dependence
In situ video STM studies of the hydrogen-induced reconstruction of Cu(100): potential and pH dependence
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DOI：
10.1039/c0cp00659a
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发表时间：
2010-01-01
影响因子：
3.3
通讯作者：
Magnussen, Olaf M.
中科院分区：
文献类型：
--
作者：
Matsushima, Hisayoshi;Haak, Christian;Magnussen, Olaf M.
用视频速率扫描隧道显微镜研究了Cu（100）电极在pH 1 ~ 3的高氯酸溶液中析氢电位范围内的表面结构，重点研究了最近报道的氢致表面重构[H. Matsushima等人，J. Am. 2009，131，10362]。电位依赖的测量揭示了两个步骤的形成过程：在电位接近的开始析氢的p（1 × 8）相出现，其中铜表面原子在条状结构的横向和垂直位移;在约30 mV的负电位的过渡到c（p × 8）结构与扩展的铜表面晶格发生。这些观察结果与电化学数据的相关性以及在真空条件下氢与Cu（100）表面相互作用的研究支持这些相是由氢在表面下的位点诱导的，指向在反应条件下该电极表面上的高氢覆盖。
The surface structure of Cu(100) electrodes in perchloric acid solutions of pH 1 to 3 was studied in the potential range of hydrogen evolution by video-rate scanning tunneling microscopy, focusing on the recently reported hydrogen-induced surface reconstruction [H. Matsushima et al., J. Am. Chem. Soc. 2009, 131, 10362]. Potential-dependent measurements reveal a two step formation process: at potentials close to the onset of hydrogen evolution a p(1 x 8) phase emerges, where Cu surface atoms in stripe-like structures are laterally and vertically displaced; at approximate to 30 mV more negative potentials a transition to a c(p x 8) structure with an expanded Cu surface lattice occurs. Correlation of these observations with electrochemical data and studies on hydrogen interactions with Cu(100) surfaces under vacuum conditions support that these phases are induced by hydrogen in subsurface sites, pointing towards a high hydrogen coverage on this electrode surface under reaction conditions.