Platinum-free Catalyst for Efficient Reduction of Oxygen at Air Cathode

Abstract Electrocatalytic activity and selectivity for oxygen reduction to water on platinum-free catalysts prepared from transition metal hexacyanometallate precursors have been examined using a rotating ring-disk electrode technique. The results obtained indicated that a catalyst containing copper and iron promotes so-called four-electron reduction reaction of oxygen at a potential close to or higher than that of a Pt electrode, so that it could be a possible candidate substituting for Pt-based catalysts of air cathodes.