Adsorbate-oxide interactions during the NO + CO reaction on MgO(100) supported Pd monolayer films

The potential energy diagram for the NO+CO reaction on 1, 2, and 3 monolayer (ML) Pd films supported by MgO(100) is calculated using density functional theory. Thin Pd films are generally found to be more reactive than thick films, with a notable exception for nitrogen adsorption on 2 ML Pd/MgO(100). For this system an attractive through-the-metal adsorbate-oxide interaction of 0.5 eV is identified. Nitrogen adsorption is consequently estimated to provide a thermodynamic driving force for the reconstruction of MgO(100) supported 3 ML (or thicker) Pd clusters into thinner Pd clusters.