Effects of the metal in the adsorption of NO2 on platinum supported BaO films

Density functional calculations are reported for NO2 adsorption on BaO(1 0 0) films supported on Pt. The metal is predicted to largely stabilize NO2 adsorption. The phenomenon is most pronounced for a two layer BaO film, but clearly present for films as thick as five oxide layers. From the different contributions to the adsorption energy, the stabilization is found to originate from an increased oxide-metal bonding. The results stress the complex nature of molecular-surface interactions in multi-component systems, and have implications for the understanding of surface processes in heterogeneous catalysis.