Background

The appeal of using abundant resources, such as solar energy and water, to produce chemical fuels has increased the urgency to optimize all aspects of the photoelectrolysis of water. The anodic water oxidation half-reaction is particularly challenging, and catalysts are necessary to overcome its kinetic sluggishness. Metal oxides of nonprecious metals are a promising class of catalyst for the OER reaction in alkaline electrolytes, and compositions containing more than one type of metal ion are particularly promising. Combinatorial screening methods are an attractive approach to discovering new mixed metal OER catalysts.