MIXED METAL OXIDES FOR THE EFFICIENT CATALYSIS OF THE ELECTROCHEMICAL OXYGEN EVOLUTION REACTION

Abstract

The splitting of water into hydrogen and oxygen using electricity generated from solar and wind farms is a promising way to produce hydrogen gas as a green fuel. The oxygen evolution reaction (OER) is the bottleneck half-reaction that reduces the efficiency of water splitting. Mixed metal oxides are highly promising candidates for the catalysis of the OER. In this thesis, the Ir/Ni oxide+Fe(3+) catalytic system and CoOx+Fe(3+) catalytic system were presented to be efficient OER catalysts. The reasons for their excellent OER stability and activity were elucidated and the active sites were identified. The synergistic effect towards OER was found to commonly exist between Fe and five other metal (Co, Ni, Cu, Ag, Au) oxides and the possible causes for this synergistic effect were explored. Iron site is proposed to be the principal active site in all these synergistic systems.