X-ray photoelectron spectroscopy and scanning tunnel microscope studies of formate species synthesized on Cu(111) surfaces
X-ray photoelectron spectroscopy and scanning tunnel microscope studies of formate species synthesized on Cu(111) surfaces
复制标题
Cu(111)表面合成甲酸盐的X射线光电子能谱和扫描隧道显微镜研究
DOI：
10.1116/1.580633
复制
发表时间：
1997
期刊：
影响因子：
--
通讯作者：
T. Fujitani
中科院分区：
文献类型：
--
作者：
J. Nakamura;Y. Kushida;Y. Choi;T. Uchijima;T. Fujitani
利用X射线光电子能谱和扫描隧道显微镜研究了常压下CO2加氢在Cu（111）表面生成甲酸盐物种的过程。在PH 2 =PCO2=380 Torr和333 K时，甲酸盐的初始形成速率测得为2.1×10−4 molecules site−1 s−1。甲酸盐物种的饱和覆盖率估计为ΘHCOO=0.24，其中Θ=1对应于Cu表面原子的数目。没有观察到Zn对在Cu（111）表面上形成甲酸盐物质的促进作用，表明先前观察到的Zn对在Cu（111）上甲醇合成的促进作用不是归因于甲酸盐形成中的促进，而是归因于甲酸盐物质的氢化过程中的促进。在pH = PCO_2 =380 Torr和333 K条件下，CO_2在Cu（111）表面氢化20 min，得到了甲酸盐在Cu（111）表面上的STM图像。
The synthesis of formate species on Cu(111) surfaces by hydrogenation of CO2 at atmospheric pressure was studied by x-ray photoelectron spectroscopy and scanning tunnel microscope (STM). The initial formation rate of formate was measured to be 2.1×10−4 molecules site−1 s−1 at PH2=PCO2=380 Torr and 333 K. The saturation coverage of formate species was estimated to be ΘHCOO=0.24, where Θ=1 corresponded to the number of Cu surface atoms. No promotional effect of Zn on the formation of formate species over a Cu(111) surface was observed, indicating that the promotional effect of Zn previously observed for methanol synthesis on Cu(111), is not ascribed to promotion in the formate formation, but is ascribed to promotion in a hydrogenation process of formate species. STM images were obtained for individual formate species synthesized on a clean Cu(111) surface by hydrogenation of CO2 at PH2=PCO2=380 Torr and 333 K for 20 min. Formate species arranged in a hexagonal structure with a distance of 6.6±0.2 A were att...