Carbon-supported platinum-molybdenum electro-catalysts for methanol oxidation

The synthesis and characterization of catalysts based on bimetallic materials, Pt-Mo supported on carbon for the anodic oxidation of methanol in direct methanol fuel cells is reported here. The catalysts were synthesized from the Pt carbonyl complex ([Pt3(CO)3 (μ2-CO)3]n2−), prepared by bubbling CO through a chloroplatinic acid solution. The supported Pt-Mo/C materials were prepared in a reflux system, by mixing different amounts of Mo hexacarbonyl complex, Pt-carbonyl complex and carbon, using o-xylene as solvent. The Pt-Mo/C materials were characterized by cyclic voltammetry (CV) in methanol, formaldehyde and formic acid solutions with H2SO4 as supporting electrolyte. Rotating disk electrode (RDE) voltammetry tests were carried out to determine the electric potentials in which the electrode reactions involve a diffusion process. The highest activity towards anodic methanol oxidation was obtained with materials with low molybdenum loadings.