A comparative ab initio pseudopotential study of the adsorption and migration profiles of single neutral Pt and Au atoms on the stoichiometric and reduced TiO2 rutile (110) surfaces was presented. Pt and Au behaved similarly with respect to (i) most favorable adsorption sites, (ii) the large increase in their binding energy when the surface was reduced, and (iii) their low migration barrier on the stoichiometric surface. Pt, on the other hand, bonded more strongly (by ∼2eV) to both surfaces. On the stoichiometric surface, Pt migration pattern was expected to be one-dimensional, which was primarily influenced by interactions with O atoms. The Au migration was expected to be two-dimensional, with Au-Ti interactions playing a more important role. On the reduced surface, the migration barrier of Pt trapped at an O vacancy site was significantly larger compared to that of Au.

Adsorption and Diffusion of Pt and Au on the Stoichiometric and Reduced TiO2 Rutile (110) Surfaces. Iddir, H., Öğüt, S., Browning, N.D., Disko, M.M.: Physical Review B, 2005, 72[8], 081407