Manganese oxide-based heterogeneous electrocatalysts for water oxidation
Water oxidation is considered an important reaction to attain sustainable energy systems. Inspired by the biological Mn4CaO5 cluster, considerable effort has been devoted to developing efficient manganese-based heterogeneous catalysts for the water oxidation reaction. This review first describes the structural characteristics of the Mn4CaO5 cluster and synthetic manganese oxides. Important features related to the electrocatalytic activity of manganese-based heterogeneous catalysts as well as recent in situ spectroscopic results for intermediate characterization are then summarized. Current understanding of the reaction mechanism at the atomic level and the rate-determining step is highlighted. Finally, future perspectives for the development of highly active and stable manganese-based water-oxidizing catalysts are proposed.