Pd, Rh, Ir and Pt adsorption on gold: A theoretical study of different surfaces

The interaction of atomic Pd, Rh, Ir and Pt with the Au(1 1 1) and Au(1 0 0) surfaces is studied by ab-initio density functional calculations within the generalized gradient approximation (GGA). For the two surfaces, we have determined the preferred adsorption sites, the adsorption structures, spin-projected density of states and local magnetic moments, including relaxation effects. This study allows some common features to be seen, in particular in the adsorption energies and geometries for both surfaces and some significant differences such as the considerable broadening of the impurity atom bandwidth on the Au(1 0 0) surface. The origin of these differences is explained by an analysis of the electronic structures of both surfaces.