A synergistic strategy of Fe doping and anion protection enables efficient and robust seawater electrolysis

Abstract

Seawater electrolysis is a promising method for producing hydrogen, but the generation of corrosive chlorine species (e.g., chloride and hypochlorite) remains a critical challenge. Herein, we successfully synthesized a FeNiP/MoOx/NiMoO4/NF electrocatalyst through Fe doping and subsequent phosphidation of NiMoO4/NF, which exhibits exceptional activity and stability for alkaline seawater oxidation. FeNiP/MoOx/NiMoO4/NF requires an overpotential of 349 mV to reach a current density (j) of 1000 mA cm−2, showing constant operation for 500 h at the same j. Furthermore, an anion-exchange membrane electrolyzer equipped with FeNiP/MoOx/NiMoO4/NF demonstrates excellent performance, requiring only 2.12 V to achieve 300 mA cm−2 while maintaining stable operation for 180 h.