An EQCN assessment of electrocatalytic oxidation of methanol at nanostructured Au¯Pt alloy nanoparticles

Alloy nanocrystals encapsulated with alkyl dithiolates ("core-shell" nanoparticles) serve as an intriguing class of nanostructured catalysts. This paper reports the preliminary results of an electrochemical quartz-crystal nanobalance (EQCN) investigation of mass transport associated with the catalytic activation and methanol oxidation at nanostructured Au¯Pt nanocrystals. It is demonstrated that the catalytic activation and oxidation of methanol are accompanied by mass fluxes across the nanostructured film. The mass transport involves oxidation¯reduction of surface oxygenated species, methanol adsorption and oxidation, solvent breath and product release. The implication of the EQCN results to the understanding of the core-shell nanostructured catalytic mechanism is discussed.