Gas binding to Au13, Au12Pd, and Au11Pd2 nanoclusters in the context of catalytic oxidation and reduction reactions

The ability of Au(13), Au(12)Pd, and Au(11)Pd(2) nanoclusters to bind species typically found in the oxidation and reduction of small hydrocarbon has been investigated by means of atom centered density functional theory calculations. Binding energies of CO(2), H(2), CO, O(2), CH(4), H(2)O, *O, *H, *CHO, *CO(2)H, and *OH have been calculated. For pure gold nanoclusters, CO(2), H(2), and CH(4) were found to not bind, and O(2) and H(2)O bound weakly with binding energies less than 15 kcal mol(-1), with the rest binding strongly with binding energies in the range 26-68 kcal mol(-1). Binding additional gas molecules did not greatly reduce the binding energy. Adding palladium to the clusters created binding sites for all of the test gases. Binding to the palladium atom generally increased the binding energy of molecules but decreased the binding energy of radicals.