Partially Amorphous Ru‐Doped CoSe Nanoparticles with Optimized Intermediates Adsorption for Highly Efficient Sulfur Oxidation Reaction

Abstract The application of thermodynamically more favorable sulfur oxidation reaction (SOR) to replace oxygen evolution reaction (OER) in electrocatalytic water electrolysis is an appealing strategy to achieve low‐energy hydrogen production while removing toxic sulfur ions from wastewater. However, the study of SOR catalysts with both activity and stability still faces great challenges. Herein, this study prepares partially amorphous Ru‐doped CoSe (pa‐Ru‐CoSe) nanoparticles for SOR. The doping of Ru keeps Co in an electron‐deficient state, which enhances the adsorption of SOR intermediates and improves the catalytic activity. Meanwhile, the partially amorphous selenide possesses great corrosion resistance to sulfur species, thus ensuring stability in long‐term SOR. In addition, the pa‐Ru‐CoSe requires only 0.566 V to reach a current density of 100 mA cm −2 in the SOR‐HER coupled system and remains stable for 200 h. This work provides a promising partially amorphous strategy for SOR catalysts with both catalytic activity and long‐term stability, enabling hydrogen production with low energy consumption and simultaneous sulfur production.