Engineered PW12-polyoxometalate docked Fe sites on CoFe hydroxide anode for durable seawater electrolysis
Xun He, Yongchao Yao, Min Zhang, Yilei Zhou, Limei Zhang, Yuchun Ren, Kai Dong, Hong Tang, Jue Nan, Xin Zhou, Han Luo, Binwu Ying, Qi Yu, Fengming Luo, Bo Tang, Xuping Sun
Abstract
Abstract Seawater electrolysis driven by offshore renewable energy is a promising avenue for large-scale hydrogen production but faces challenges in designing robust anodes that suppress surface chlorine reactions and corrosion at high current densities. Here we report a strategy by selectively docking PW 12 -polyoxometalate (PW 12 -POM) onto Fe sites of CoFe hydroxide anode to modulate the electronic structure of adjacent Co active centers and regulate Cl⁻/OH⁻ adsorption for efficient alkaline seawater oxidation. Our CoFe-based anode achieves low overpotentials, high catalytic selectivity, and notable durability, with continuous operation at 1 A cm⁻² for over 1300 hours and at 2 A cm⁻² more than 600 hours. Theoretical calculations and ex situ/in situ analyses reveal that PW 12 -POM coordination at Fe sites stabilizes Fe, suppresses its leaching, modulates Co acidity, promotes OH⁻ adsorption, and protects metal sites from Cl⁻ corrosion.