Skoda M, Cabala M, Matolínová I, Prince K C, Skála T, Sutara F, Veltruská K, Matolín V
Charles University, Faculty of Mathematics and Physics, Department of Surface and Plasma Science, V Holesovickach 2, 18000 Prague 8, Czech Republic.
J Chem Phys. 2009 Jan 21;130(3):034703. doi: 10.1063/1.3046684.
We have studied the adsorption of low dimensional gold on ceria, produced by evaporation onto the surface. The interaction of gold with CeO(2)(111) layers was investigated with x-ray photoemission spectroscopy, ultraviolet photoemission spectroscopy, and resonant photoelectron spectroscopy (RPES). Gold was deposited in steps onto a 1.5 nm thick CeO(2)(111) layer epitaxially grown on a Cu(111) substrate. The RPES showed a partial Ce(4+)-->Ce(3+) reduction, observed as a resonant enhancement of the 4f level of the Ce(3+) species. This can be explained by possible creation of a new Au(+) ionic state. The observed effects are stronger for Au deposition at room temperature than at 250 degrees C. The obtained results are in agreement with already published density functional theory calculations reporting weakening of bond between the oxygen and the Ce atoms in ceria caused by the presence of gold.
我们研究了通过蒸发到表面上在二氧化铈上形成的低维金的吸附情况。利用X射线光电子能谱、紫外光电子能谱和共振光电子能谱（RPES）研究了金与CeO₂(111)层的相互作用。金分阶段沉积在生长于Cu(111)衬底上的1.5 nm厚的CeO₂(111)层上。RPES显示出部分Ce(4+)向Ce(3+)的还原，表现为Ce(3+)物种4f能级的共振增强。这可以通过可能产生新的Au(+)离子态来解释。室温下金沉积时观察到的效应比在250℃时更强。所得结果与已发表的密度泛函理论计算结果一致，该计算报告称金的存在导致二氧化铈中氧与铈原子之间的键减弱。
