A first-principles study of NO adsorption and oxidation on Au(111) surface.
A first-principles study of NO adsorption and oxidation on Au(111) surface.
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DOI：
10.1063/1.2985668
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发表时间：
2008-10
期刊：
影响因子：
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通讯作者：
Wenhua Zhang;Zhenyu Li;Yi Luo;Jinlong Yang
中科院分区：
文献类型：
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作者：
Wenhua Zhang;Zhenyu Li;Yi Luo;Jinlong Yang
用密度泛函理论和平板模型研究了NO分子在清洁和原子氧覆盖的Au(111)表面上的吸附和反应。清洁的Au(111)表面是催化惰性的，只能弱吸附NO，而原子氧预包覆的Au(111)表面对NO具有很高的活性。在清洁的表面上，没有人喜欢在单一的顶部表面位置与倾斜的几何图形结合。在0.33ML(单层)氧表面上，NO通过克服约0.18 eV的小能垒与化学吸附的氧反应生成化学吸附的NO(2)，其脱附能为0.64 eV。在1.0ML氧覆盖表面上，未发现与预覆盖氧发生反应的势垒。NO(2)的脱附能为0.03 eV。NO(2)的脱附是两个表面的速率控制步骤，总反应势垒分别为0.64 eV和0.03 eV。活化能依赖于氧的初始覆盖度，这与在不同氧覆盖度的金表面上的实验结果是一致的。
Density functional theory and slab models are employed to study NO molecule adsorption and reaction on clean and atomic oxygen precovered Au(111) surfaces. While clean Au(111) surface is catalytically inert and can only weakly adsorb NO, an atomic oxygen precovered Au(111) surface is found to be very active to NO. On the clean surface, NO prefers to bond at the onefold on-top surface site with a tilted geometry. On 0.33 ML (monolayer) oxygen precovered surface NO reacts with chemisorbed oxygen to form chemisorbed NO(2) by conquering a small energy barrier about 0.18 eV, and the desorption energy of NO(2) is 0.64 eV. On 1.0 ML oxygen coverage surface, no barrier is found while NO reacts with precovered oxygen. The desorption energy of NO(2) is 0.03 eV. The desorption of NO(2) is the rate determining step on both surfaces and the overall reaction barriers are 0.64 and 0.03 eV, respectively. The activation energies depend on the initial coverage of oxygen, which compare favorably with experiments on Au surface with different oxygen coverages.