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 m(2)/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 (WO(x), MoO(x), VO(x)) leads to an improvement of the catalytic activity towards methanol oxidation. (C) 1999 Elsevier Science S.A. All rights reserved.