The Electrokinetics of CO Oxidation on Pt[sub 4]Mo(20 wt %)∕C Interfaced with Nafion Membrane

Abstract

The bimetallic, electrocatalyst prepared by the colloidal aluminum-organic reductive-stabilization pathway by the Bönnemann's group (unpublished) was studied by means of X-ray photoelectron spectroscopy (XPS) and electrochemical measurements aiming to a deeper insight on the structure, chemical state, catalytic and electrocatalytic functioning under mixtures. Combined XPS and sputtering experiments revealed that Mo and Pt form bulk alloy nanoparticles, the surface of which is enriched with Pt atoms, while , or species exist on the nanoparticles' surface. nanoparticles are shown to be able to electrochemically oxidize at very low potential that coincides with the oxidation potential. This unique property depends on the oxidation state of the Mo surface species and specifically on the reactive species of and its attribute to spontaneously dissociate . Due to this property nanoparticles can catalyze the water-gas shift reaction at temperatures as low as . However, the operation of the electrocatalyst at potentials higher than , with respect to the electrode voltage, results in the formation of and the deactivation of the low potential oxidation sites.