Investigation of Pt–Ru nanoparticle catalysts for low temperature methanol electro-oxidation

Pt–Ru nanoparticle-based methanol electro-oxidation catalysts with high concentration of metallic phase on carbon black have been synthesised by a low-temperature colloidal preparation route. Amorphous Pt–Ru oxide nanoparticles were deposited on carbon and subsequently reduced in hydrogen stream at different temperatures to obtain crystalline phases with tailored particle size. The electro-catalytic activity for methanol oxidation was investigated in half-cell from 30 to 60 °C. The results were interpreted in terms of particle size, crystallographic structure, degree of alloying and carbon monoxide adsorption properties. The best performance was achieved for the catalyst with intermediate particle size in the investigated range. Furthermore, it is observed that the optimal properties for these catalysts depend on the operating temperature.