Achieving efficient and robust seawater oxidation through rational design of V2O3/NiFeP composite

Abstract

Direct seawater electrolysis has potential in green hydrogen production; however, its anode is susceptible to chloride-induced corrosion, limiting its durability. Herein, using nickel foam (NF) as a catalyst support, we developed a V₂O₃/NiFeP/NF anode for alkaline seawater oxidation. During the oxygen evolution reaction, NiFeP generates phosphate ions (PO₄³⁻), which electrostatically repel chloride ions (Cl⁻). As a Lewis acid, V₂O₃ enriches OH⁻ on the surface, thereby enhancing catalytic activity and facilitating Cl⁻ repulsion. At an industrial-scale current density of 1000 mA cm⁻², V₂O₃/NiFeP/NF requires only 335 mV of overpotential and operates stably for 1000 h with negligible degradation and a small amount of active chlorine generation. The membrane electrode assembly electrolyzer, comprising a V₂O₃/NiFeP/NF anode and a Pt/C/NF cathode, exhibits stable operation at 300 mA cm⁻² for 250 h.