Electrochemically Codeposited Platinum/Molybdenum Oxide Electrode for Catalytic Oxidation of Methanol in Acid Solution

Abstract

An electrochemical codeposition method was used to prepare a composite electrode which provides a surface modification with catalytic properties for methanol oxidation in acid solution. This method allows the mixing of metal and support on a microscopic level (atomic or molecular scale), i.e., to disperse the microparticles into the molybdenum oxide on a carbon (C) substrate. X‐ray photoelectron spectroscopy of the composite electrode presented a broad peak in the region revealing the existence of species as well as lower valence states such as and . Cyclic voltammetry, potentiodynamic voltammetry, and the potentiostatic techniques were also used to characterize the electrode. The composite electrode showed a better performance for methanol oxidation in acidic media than on platinized carbon electrode. A surface redox mechanism which involves (i) the couple in substoichiometric lower valence molybdenum oxides and (ii) the proton spillover effect from hydrogen molybdenum bronze are two possible explanations for the enhanced catalytic activity of this system. ©1999 The Electrochemical Society