Manganese based transition metal oxide catalysts for oxygen electrodes in fuel cells

Abstract

Fuel cells are efficient energy sources that convert chemical energy stored inside the fuel into electrical energy. They are environmentally benign in operation as no SO2 or NO is produced. Potential markets include the automotive industry, computers, and wireless communications. Fuel cells have remained costly, however, because they incorporate expensive platinum catalysts to accelerate the oxidation reaction of fuels at the anode and the reduction reaction of oxygen gas at the cathode. Using precipitation methods, we attempted to synthesize catalysts out of more affordable amorphous manganese dioxide, both pure and doped with nickel. The amorphous manganese dioxide shows promising potential as an oxygen reduction catalyst for low power fuel cells. The effect of nickel doping on the catalytic performance manganese dioxide was investigated. The nickel-doped manganese oxide gives poorer performance than the pure amorphous manganese oxide because the average spacing of transition metal cations is changed and the catalytic ability is weakened as a consequence of this change.