Porous Mn2 O3 : A Low-Cost Electrocatalyst for Oxygen Reduction Reaction in Alkaline Media with Comparable Activity to Pt/C

Preparing nonprecious metal catalysts with high activity in the oxygen reduction reaction (ORR) can promote the development of energy conversion devices. Support-free porous Mn2 O3 was synthesized by a facile aerosol-spray-assisted approach (ASAA) and subsequent thermal treatment, and exhibited ORR activity that is comparable to commercial Pt/C The catalyst also exhibits notably higher activity than other Mn-based oxides, such as Mn3 O4 and MnO2 . The rotating ring disk electrode (RRDE) study indicates a typical 4-electron ORR pathway on Mn2 O3 . Furthermore, the porous Mn2 O3 demonstrates considerable stability and a good methanol tolerance in alkaline media. In light of the low cost and high earth abundance of Mn, the highly active Mn2 O3 is a promising candidate to be used as a cathode material in metal-air batteries and alkaline fuel cells.