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Interaction of Au with CeO2(111): A photoemission study

2009; American Institute of Physics; Volume: 130; Issue: 3 Linguagem: Inglês

10.1063/1.3046684

1520-9032

M. Škoda, M. Cabala, Iva Matolı́nová, Kevin C. Prince, Tomáš Škála, F. Šutara, Kateřina Veltruská, Vladimı́r Matolín,

Analytical chemistry methods development

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.