Highly defective CeO2 as a promoter for efficient and stable water oxidation

A highly defective CeO₂ supported RuO₂ as an electrocatalyst shows improved OER activity and stability in alkaline media. This improvement likely originates from the highly oxidative oxygen species O₂²⁻/O⁻ formed in the defective CeO₂, which can easily migrate from CeO₂ and “spillover” to the surface of RuO₂ during the OER process.