Surface amorphization enables robust catalyst for industrial-level low-potential electrooxidation reactions
Jian Chen, Xin Wang, Chang Sun, Zheng Li, Yangen Zhou, Xijun Li, Yumin Qian, Mengran Wang, Simin Li, Yanqing Lai, Shuangyin Wang
Abstract
Electrooxidation of pollutants at potentials near or below the thermodynamic hydrogen evolution potential offers transformative opportunities for energy-efficient pollutant valorization and diverse energy devices. However, existing catalysts suffer from rapid deactivation due to the inevitable overoxidation. Herein, we present an amorphous phosphorus-doped CoFe₂O₄ catalyst that achieves industrial-level current densities (1 A cm⁻²) at ultralow potentials (0.06, 0.65, and −0.17 V vs. reversible hydrogen electrode) for hydrazine, sulfion, and borohydride electrooxidation, respectively, along with 400-hour stability at 300 mA cm⁻² in a hydrazine-assisted electrolyzer. Mechanistic studies reveal electron transfer from Co-P ligands to Co-O ligands, which enhances the involvement of Co-O ligands in low-potential electrooxidation while protecting Co-P ligands from overoxidation. Furthermore, more positive charges on Co centers lower the activation barrier for such pollutant electrooxidation. This work opens a paradigm for designing robust electrocatalysts by decoupling catalytic activity from oxidative deactivation. Electrooxidation of pollutants near or below the thermodynamic hydrogen evolution potential offers transformative opportunities for energy-efficient devices. Here, the authors report amorphous phosphorus-doped CoFe2O4 catalysts for stable industrial level low-potential electrooxidation reactions.