| Abstract
| - We have used computer modeling techniques to investigate the interaction of Cu, Ag, and Au atoms (at 0.25ML coverage) with the (111) surface of zirconia, ZrO2. The surface was simulated by means of periodicslabs, and the calculations were performed using spin-polarized density functional theory (DFT) within thegeneralized gradient approach. We show that, for the three metals, the most stable adsorption sites are not ontop of the outmost oxygen atoms, as previously suggested for the Cu/ZrO2 case, but at less-symmetric bridgesites between oxygen and zirconium. Furthermore, the examination of the charge density and the electronicdensity of states shows that no full charge transfer takes place between any of the metals and the zirconiasurface, as, in all cases, the metal's unpaired electron remains largely localized on the metal adatom uponadsorption. The origin of the interaction appears to be the polarization of the electronic density of the adsorbedmetal atom, together with a modest chemical contribution arising from the mixing of the orbitals of the metalatom and the surface oxygen. The adsorption energies follow the order |Eads(Ag)| < |Eads(Au)| < |Eads(Cu)|.
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