Atomically Ru-Doped Co₃O₄ With Asymmetric Ru-O-Co Sites for High-Performance Chlorine Evolution

Chlorine production remains foundational to chemical manufacturing, yet its electrochemical generation is hindered by sluggish kinetics and unfavorable intermediate adsorption-desorption dynamics. Here, we fabricate atomically Ru-doped Co₃O₄ featuring asymmetric Ru-O-Co bridge sites, in which isolated Ru atoms are incorporated into the Co₃O₄ spinel lattice to regulate the local coordination environment and electronic structure. In situ spectroscopic characterizations combined with first-principles calculations reveal that Ru substitution disrupts the rigid symmetric Co-O-Co configuration and weakens the excessively strong Co-Cl interaction. The relatively weak Ru 4p-O 2p coupling endows Ru sites with abundant accessible vacant orbitals, favoring the formation of labile Ru-Cl species and enabling rapid and reversible Cl adsorption-desorption cycling while suppressing stable Co-Cl intermediates. Such asymmetric electronic modulation accelerates chlorine evolution kinetics and promotes a Ru-dominant Volmer-Heyrovský pathway with reduced energy barriers. Benefiting from the optimized active-site configuration, RuO_x-Co₃O₄ with an ultralow Ru loading of only 1.64 wt.% delivers substantially higher CER activity than commercial dimensionally stable anodes (DSA), achieving a mass activity of 3049 A g_Ru ^-1 and a Cl₂ selectivity of 98.9% at 1.5 V. This work highlights asymmetric site engineering as an effective strategy for developing highly efficient and selective CER electrocatalysts.