Water Oxidation Mechanism for 3d Transition Metal Oxide Catalysts under Neutral Condition

Electrochemical water splitting to produce hydrogen energy is regarded as a promising energy conversion process for its environmentally friendly nature. To improve cell efficiency, the development of efficient water oxidation catalysts is essentially demanded. For several decades, 3d transition metal oxides have been intensively investigated for their high activity, good durability and low-cost. This review covers i) recent progress on 3d transition metal oxide electrocatalysts and ii) the reaction mechanism of oxygen evolving catalysis, specifically focused on the proposed pathways for the O-O bond formation step. Key words: Transition metal oxides, Electrodes, Water oxidation, Electrocatalyst, O-O bond formation