Copper-ceria interaction: A combined photoemission and DFT study

Stoichiometric and partially reduced ceria films were deposited on preoxidized Ru(0 0 0 1) crystal by Ce evaporation in oxygen atmosphere of different pressures at 700 K. Copper-ceria interaction was investigated by deposition of metalic copper on both types of substrate. The samples were characterized by low energy electron diffraction (LEED), X-ray photoelectron spectroscopy (XPS) of core states and resonant photoelectron spectroscopy (RPES) of the valence bands. Copper adsorption on stoichiometric ceria caused reduction of CeO2, while on the oxygen-defficient ceria it partially reoxidized the substrate. This is in agreement with DFT+U calculations of copper adsorption on stoichiometric and defective ceria surfaces.

► Copper-ceria system as model catalyst. ► Cu was deposited on stoichiometric and partially reduced ceria surfaces on Ru(0 0 0 1). ► Reduction of stoichiometric ceria was observed upon copper deposition. ► Copper reoxidates partially reduced ceria surface. ► Described copper-ceria interaction predicted by DFT+U calculations.