Chemisorbed Oxygen on the Au(321) Surface Alloyed with Silver: A First-Principles Investigation
Chemisorbed Oxygen on the Au(321) Surface Alloyed with Silver: A First-Principles Investigation
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DOI：
10.1021/jp511884k
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发表时间：
2015-04
影响因子：
3.7
通讯作者：
L. Moskaleva;Theodor Weiss;T. Klüner;M. Bäumer
中科院分区：
文献类型：
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作者：
L. Moskaleva;Theodor Weiss;T. Klüner;M. Bäumer
采用密度泛函理论研究了氧在扭折Au（321）平板上的吸附。在表面上，次表面和表面氧化物形式的O进行了分析和比较，纯金和表面上含有银原子。在低O覆盖率（0.1 ML）的次表面O物种被证明是不稳定的，由于转化为更强的结合表面上的化学吸附氧的低势垒的热力学和动力学。在近表面区域中的Ag的存在下，被示出为增加表面上以及次表面O的结合强度，但是用于释放次表面O到表面的活化势垒基本上不受Ag的存在下的影响。在氧覆盖率为0.2 ML或更高时，O原子最稳定的表面排列是由线性−O-Au-O-片段组成的链状结构。作为这种链的一部分的次表面O原子被显著稳定。我们研究清洁表面和可能的稳定氧化之间的相变。
The adsorption of oxygen on kinked Au(321) slabs is investigated theoretically on the basis of density functional theory. On-surface, subsurface, and surface-oxide forms of O are analyzed and compared on pure gold and on the surfaces containing silver atoms. At low O coverage (0.1 ML) subsurface O species are shown to be unstable both thermodynamically and kinetically due to a low barrier for conversion to stronger bound on-surface chemisorbed oxygen. The presence of Ag in the near-surface region was shown to increase the binding strength of on-surface as well as subsurface O, but the activation barrier for releasing subsurface O to the surface remains essentially unaffected by the presence of Ag. At oxygen coverage 0.2 ML or higher, the most stable surface arrangements of O atoms are chain-like structures consisting of linear −O–Au–O– fragments. Subsurface O atoms being a part of such chains are significantly stabilized. We examine phase transitions between the clean surface and possible stable oxidized ...