The adsorption properties of Au and Pt metal nanoclusters on TiO2 anatase (101) were calculated using density functional theory. Structures and energetics of adsorbed Au and Pt monomers, dimers, and trimers at clean anatase TiO2(101) terraces and two major step edges, as well as O-vacancies, were systematically determined. The theoretical predictions were tested by vapor-depositing small coverages of Au and Pt on anatase (101) and investigating the resulting clusters with scanning tunnelling microscopy. On the clean surface, Au exhibited a strong tendency to form large clusters that nucleated on step edges. A preference for adsorption at type D-(112) steps was observed, which was probably a result of kinetic effects. For Pt, clusters as small as monomers were observed on the terraces, in agreement with the predicted large binding energy of 2.2eV. Step edges play a less important role than in the case of Au. Oxygen vacancies, produced by electron irradiation, dramatically influence the growth of Au, while the nucleation behavior of Pt was found to be less affected.

Small Au and Pt Clusters at the Anatase TiO2(101) Surface: Behavior at Terraces, Steps, and Surface Oxygen Vacancies. Gong, X.Q., Selloni, A., Dulub, O., Jacobson, P., Diebold, U.: Journal of the American Chemical Society, 2008, 130[1], 370-81