Electro-oxidation of Methanol on Fuel Cell Catalysts and Evaluation of their Catalytic Activities by Cyclic Voltammetry

The electro-oxidation of methanol on smooth pt-strip and 10 % pt supported on vulcan xc-72 was studied in acidic medium using cyclic voltammetry. the electro-oxidation of methanol gave well-defined anodic peaks in both anodic and cathodic sweeps. real surface area, roughness factor, exchange current density, peak current and the heterogeneous rate constant for electro-oxidation of methanol were found to be higher on 10 % pt-catalyst as compared with smooth pt-strip. the thermodynamic parameters, δh*, δs* and δg298* were evaluated. the value of δh* for electro-oxidation of methanol on smooth pt-strip was higher and found 57 kj mol-1, while the value of δh* on 10 % pt-catalyst was 26 kj mol-1. the more positive value of δh* obtained on smooth pt-strip was attributed to its poor catalytic activity for electro-oxidation of methanol. the values of δg298* were also positive indicating that the electro-oxidation of methanol on fuel cell catalysts was an endothermic and non-spontaneous process and hence the higher temperature might be more favorable for increasing the catalytic activity of fuel cell catalysts.