Electrochemical activity of manganese oxide/carbon-based electrocatalysts

Electrocatalysts prepared by chemical deposition of MnOx on carbon were tested successfully for the oxygen reduction reaction (ORR) in 1 M KOH solution using the rotating disk electrode (RDE). Nickel or magnesium doped MnOx/C exhibit better activity towards ORR than undoped MnOx/C. In comparison, the benchmark catalyst, 10 wt% Pt/C from E-Tek exhibits ORR activity close to those of the doped MnOx/C catalysts. We believe that the doping transition metals stabilize an intermediate Mn-III/Mn-IV phase, which favors oxygen bond splitting, and thus enhances ORR rate. In consequence these doped MnOx-based materials exhibit remarkable ORR catalytic activity.