Gold, in its nano-scale, has been found to be very effective catalyst for oxidation reactions. More recently, it was shown that supported Au-Pd catalysts can be used for solvent-free oxidations of alcohols to aldehydes using oxygen as oxidant under mild conditions. Benzyl alcohol oxidation is the most studied reaction, although it is complicated by a simultaneous dispropotionation reaction. The two processes are believed to involve different intermediates. Recent work at Cardiff has identified conitions under which it is possible to selectively suppress one of the reactions. The aim of this proposal is to understand the nature of the adsorbed species that lead to these two different reactions.