CeO2/Pt(111) interface studied using first-principles density functional theory calculations

In this contribution we present ab initio density-functional-theory (DFT) calculations for CeO2 monolayers on the Pt(111) surface. The ceria surface and ceria-metal interface are of great interest because of the oxygen-storage and release capabilities of ceria, which are widely utilized in catalysis. Both the experimentally reported 3 : 4 [(4 × 4)] and 5 : 7 [(1.4 × 1.4)] matching geometries of the CeO2/Pt(111) system are studied using the GGA +U exchange-correlation scheme. Geometry optimizations of the structures are performed, resulting in a significant corrugation of both the Pt surface as well as the ceria adlayer surface. The total energies and adsorption energies of three different adsorption geometries for the 3 : 4 type are compared to the 5 : 7 structure in terms of stability. The electronic properties and the bonding character are studied by analysis of the density of states (DOS) and of the electron density. The charge transfer occurring during adsorption is calculated using the atoms-in-molecules (AIM) method. Strong interactions are detected, which are mainly based on electrostatic interactions between the topmost Pt layer and the oxygen atoms at the interface, but also include small contributions from hybridization.