ELECTROOXIDATION OF CO AND METHANOL ON GRAPHITE-BASED PLATINUM-ELECTRODES COMBINED WITH OXIDE-SUPPORTED ULTRAFINE GOLD PARTICLES

Graphite-based Pt electrodes were combined with metal-oxide-supported ultrafine Au particles (diameter <10 nm) to improve catalytic activity for the electro-oxidation of CO and CH3OH in 1 M NaOH at 30 degrees C. These C/Fe2O3 + Au + Pt electrodes exhibited much higher catalytic activity than the electrodes without Au particles, namely graphite-based Pt(C/Pt) or graphite-based Pt + alpha-Fe2O3(C/Fe2O3 + Pt) electrodes. The electro-oxidation of CH3OH on the C/Fe2O3 + Au + Pt and C/Fe2O3(Ti-doped) + Au + Pt electrodes was deactivated to much less than that on either C/Pt or C/Fe2O3 + Pt electrodes by continuous bubbling of CO, Rather, the apparent activity was increased due to superimposed CO electro-oxidation, particularly at potentials below 500 mV/RHE. The enhancement of activity by oxide-supported Au particles can be attributed to the electro-oxidative removal of CO-like carbonaceous intermediates which were produced by the partial oxidation of CH3OH.