Electrochemical fabrication of Pt-Au-WO ₃ electrodes for direct methanol fuel cell

Pt-Au-W0 ₃ ternary electrodes with various compositions were synthesized by electrochemical method from a mixture of H ₂PtCI ₆ aqueous solution, HAuCI ₄ aqueous solution, and W-peroxo complex. Their electrocatalytic activities for methanol oxidation were investigated. Film composition was controlled by varying the concentration of each component in electrolytes. Morphology and compositional analyses of the synthesized films were performed by scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS). The catalytic activity and initial behavior of current density for methanol oxidation of the synthesized films were measured using cyclic voltammetry (CV) and chronoamperometry (CA) in a mixture of 0.5 M H ₂S0 ₄ and 0.5 M CH ₃OH solution. Electrocatalytic activity for CO oxidation was also evaluated in 0.5 M H ₂S0 ₄ solution. The activities of various electrodes for methanol oxidation were found to be strongly dependent on film composition. Pt-Au-W0 ₃ electrodes exhibited higher activity for CO oxidation than pure Pt. The addition of proper amount of Au and W0 ₃ significantly improved catalytic activity for methanol oxidation.