Platinum Electrodeposition on Conductive Diamond Powder and Its Application to Methanol Oxidation in Acidic Media

Boron-doped diamond (BDD) powder is shown to be a possible alternative to carbon as a support material for fuel cell electrocatalysts such as platinum. In this work, a Pt/BDD powder electrocatalyst was prepared via electrochemical deposition of platinum, and the electrochemical behavior was compared with that for Pt/graphite powder. Electrodes were prepared by coating polycrystalline BDD films with these electrocatalysts, with Nafion solution as a binder, and the activities for methanol oxidation were found to be comparable. The use of BDD resulted in a much higher stability of the catalyst under severe anodic conditions. Steady-state and long-time methanol oxidation polarization measurements, performed in the "floating electrode" configuration in acidic media, showed that platinum on BDD powder was less sensitive to deactivation, presumably due to CO poisoning, than was platinum on graphite powder.