CO-Induced Modification of the Metal/MgO(100) Interaction

CO-induced changes in the metal/metaloxide interaction of MgO(100)-supported palladium, silver, platinum, and gold in the form of atoms and layers have been investigated within the density functional theory. CO is found to modify the metal/MgO(100) interaction for atoms and one-atom-thick layers. Generally, the bond strength is enhanced, with the largest increase calculated for Pt (∼1 eV). For metal atoms, CO adsorption is found to increase the barrier of diffusion. The underlying mechanism for bond strengthening is traced back to a matching between the CO−metal and metal−metaloxide bond characteristics. The effect of support-induced changes for an arbitrary adsorbate−metal interaction is predicted to be small beyond three atomic layers.