ELECTROOXIDATION OF METHANOL ON GRAPHITE-SUPPORTED PEROVSKITE-MODIFIED PT ELECTRODES IN ALKALINE-SOLUTION

Graphite-supported perovskite-modified Pt electrodes exhibited much higher electrocatalytic activities than smooth Pt or graphite-supported Pt electrodes towards methanol electro-oxidation in 1 M NaOH solution at 25-degrees-C, showing zero-current potential as low as 200 mV versus the reversible hydrogen electrode. For CO oxidation the modified electrodes exhibited less positive zero-current potentials (120 and 110 mV in the case of Co- and Mn-type perovskites respectively) than the smooth Pt electrode (230 mV) or the graphite-supported Pt electrode (220 mV). The catalytic activities of the modified electrodes were found to be very stable and to remain unaffected towards the poisoning effect of CO. Rather, they could oxidize both CO and methanol simultaneously, or the methanol oxidation was enhanced by the presence of CO at highly positive potentials.