关键词: 含氧阴根离子, 酸性析氧反应, 氧化钌, 硒酸根修饰, 活性-稳定性权衡

Abstract: Anion engineering has emerged as an effective strategy for improving the activity and stability of RuO₂ catalysts toward acidic oxygen evolution reaction (OER). However, the relatively low oxidation potentials of most anionic dopants render them prone to over-oxidation and dissolution under OER conditions, limiting their long-term effectiveness. Herein, we present a surface oxyanion-engineering strategy by anchoring selenate (SeO₄^2-), a thermodynamically stable oxyanion, onto RuO₂ through interfacial Se-O-Ru linkages. Mechanistic investigations reveal that surface-bound SeO₄^2- functions as an electron-withdrawing regulator, increasing the oxidation state of Ru-O bonds, which suppresses excessive lattice oxygen participation and Ru over-oxidation during OER, ultimately enhancing catalyst durability. Simultaneously, SeO₄^2- modification promotes water dissociation and proton-transfer kinetics, leading to accelerated OER kinetics. Benefiting from these synergistic effects, the optimized SeO₄-RuO₂ exhibits substantially enhanced activity and long-term stability in acidic media and delivers excellent performance in a proton exchange membrane water electrolyzer. This work demonstrates that stable oxyanion functionalization can preserve the advantages of anion regulation while avoiding oxidation-induced structural instability, providing a new strategy for overcoming the activity–stability trade-off of RuO₂ catalysts for acidic oxygen evolution.

Key words: Oxyanion, Acidic OER, RuO₂ catalyst, Selenate modification, Activity-stability trade-off