Incorporation of CeO2 with Ni–Co mixed metal phosphide boosts electrochemical seawater oxidation performance

Abstract

Electrochemical seawater oxidation has been regarded as one of the most promising strategies for cost-efficient production of hydrogen from the standpoint of sustainability, but suffers from a competitive chlorine evolution/oxidation reaction. Herein, we report a facile hard templated route to fabricate CeO₂ incorporated Ni–Co mixed metal phosphide embedded in a carbon matrix (CeO₂–Co_2−xNi_xP@C). Benefiting from compositional and structural features, the obtained CeO₂–Co_2−xNi_xP@C possesses remarkably improved OER performance in 1 M KOH (η = 295 mV at 10 mA cm⁻²) compared with Co_2−xNi_xP@C. More importantly, the catalytic activity and stability is retained well after changing fresh water to seawater to constitute the working electrolyte. The promotion effect of CeO₂ can be attributed to its unique capability in regulating the surface state of catalysts, contributing to efficient inhibition of chlorine competition.