Electrocatalytic activities of graphite-supported platinum electrodes for methanol electrooxidation

Electrooxidation of methanol in 1 M NaOH at 30 degrees C was studied on graphite-supported platinum electrodes prepared both in hydrogen and in air at various temperatures. Heating in hydrogen always; produced higher surface area of Pt, and hence greater mass activity, than in air at a particular temperature. Nevertheless, both the graphite-supported platinum electrodes exhibited almost the same specific activity as a smooth Pt electrode for methanol electrooxidation irrespective of the preparation conditions. This indicates that the difference in mass activity is due to different surface areas produced by the different preparation methods. The Tafel slope of 1 10 mV decade(-1) on all the electrodes studied indicated that the first charge transfer process was the rate-determining step.