Reduced Graphene Oxide Supported Palladium Nanoparticles for Enhanced Electrocatalytic Activity toward Formate Electrooxidation in an Alkaline Medium

The development of alkaline anion exchange membranes (AEM) has allowed for a myriad of new liquid fuels to be used in fuel cell applications that cannot be effectively oxidized under acidic conditions using proton exchange membrane fuel cells (PEMFCs). Moreover, many of these fuels are readily electrooxidized by non-platinum group metal catalysts under basic conditions. Interested in the direct formate fuel cell (DFFC), we have explored the activity of palladium supported on reduced graphene oxide (Pd/rGO) toward the formate oxidation reaction in the alkaline medium. The reduction of GO to rGO and synthesis of Pd nanoparticles were confirmed using X-ray diffraction, Raman, and X-ray photoelectron spectroscopies. The surface morphology was evaluated by scanning electron microscopy and transmission electron microscopy. Half-cell studies demonstrated superior electrocatalytic activity and stability toward formate electrooxidation for Pd/rGO than commercial Pd/C catalysts. A low metal loading AEM DFFC, fabricated with a Pd/rGO anode catalyst, displayed a 15% increase in maximum power density at 60 °C compared to the commercial Pd/C catalyst.