The effect of metal oxides as co-catalysts for the electro-oxidation of methanol on platinum–ruthenium

The electrocatalytic activities of different ternary platinum–ruthenium (Pt–Ru)–metal-oxides have been investigated in half cell experiments, by cyclic voltammetry and stationary current–voltage measurements. The results are compared to binary Pt–Ru alloy catalysts. The materials have been prepared using a modification of the Adams method. X-ray analytical methods (X-ray diffraction, XRD; energy dispersive X-ray spectroscopy, EDX; X-ray photoelectron spectroscopy, XPS) have been used to characterize the composition, particle size and crystallinity of the catalysts, and their surface areas have been determined by the Brunauer–Emmet–Teller (BET) method. The catalyst materials consist of varying amounts of metal oxides and Pt–Ru alloy particles. BET surface areas of 80–120 m2/g have been measured corresponding to particle diameters of the order of 3–5 nm. The results of electrochemical measurements demonstrate that introduction of a transition metal oxide (WOx, MoOx, VOx) leads to an improvement of the catalytic activity towards methanol oxidation.