Photoinduced Elimination of Oxygen at Ag(110)-p(2 × 1)-O: The Role of Surface Carbon Species
Photoinduced Elimination of Oxygen at Ag(110)-p(2 × 1)-O: The Role of Surface Carbon Species
复制标题
Ag(110)-p(2 × 1)-O 处氧的光诱导消除：表面碳物种的作用
DOI：
10.1021/jp010934p
复制
发表时间：
2001
影响因子：
3.3
通讯作者：
Y. Matsumoto
中科院分区：
文献类型：
--
作者：
M. Ohta;and Kazuya Watanabe;Y. Matsumoto
用X射线光电子能谱、俄歇电子能谱、低能电子衍射、光脱附质谱和程序升温脱附等方法研究了Ag(110)-p(2×1)-O表面的光诱导氧消除。在室温下紫外光照射(λ≤40 0 nm)后，只有当表面含有碳化物碳时，氧的覆盖率降低，Ag−O链的结构从p(2×1)变为p(4×1)。相反，如果表面是无碳的或含有石墨碳，则不能有效地进行光消除氧。反应截面的波长依赖性表明底物介导的激发是光化学的主要原因。光照射使氧原子以CO_2的形式被消除，表明Ag-−O链上的活性氧原子与表面的碳化碳原子反应生成CO，而CO进一步被氧化成CO_2。作为光化学的一个副作用，一些碳化碳…
Photoinduced elimination of oxygen at a Ag(110)-p(2 × 1)-O surface has been studied by X-ray photoelectron spectroscopy, Auger electron spectroscopy, low energy electron diffraction, photodesorption mass spectrometry, and temperature-programmed desorption. Upon UV photoirradiation (λ ≤ 400 nm) at room temperature the coverage of oxygen decreases and the structure of Ag−O chains changes from p(2 × 1) to p(4 × 1) only if the surface contains carbidic carbon. In contrast, the photoelimination of oxygen does not take place effectively if the surface is carbon free or contains graphitic carbon. The wavelength dependence of the reaction cross section suggests that substrate-mediated excitation is responsible for the photochemistry. Oxygen atoms are eliminated in the form of CO2 by the photoirradiation, indicating that an activated oxygen atom in the Ag−O chain reacts with a carbidic carbon atom at the surface to form CO that is further oxidized to CO2. As a side effect of the photochemistry, some carbidic carbo...