Effective chlorine and reactive oxygen species (ROS) are vital for oxidative wastewater remediation, yet conventional electrocatalysts often face activity and selectivity trade-offs. Here, a grain boundary (GB) engineering strategy is used to construct RuIrSnCoNbOx multicomponent oxides, achieving 97.0% Faradaic efficiency (FE) and over 1400 h of stability for chlorine evolution under acidic conditions. The electrocatalyst also enables simultaneous generation of effective chlorine and ROS in simulated tap water, sustaining 87.7% FE with stability approaching 160 h. Density functional theory (DFT) reveals that the RuIrSnCoNbOx GB structure facilitates dual pathways, with chlorine produced via OCl* (ηTD = 0.96 V) and ROS via the adsorbate evolution mechanism (ηTD = 1.08 V), consistent with in situ *OOH detection. Integrated into a continuous flow electrolyzer, the system ensures efficient mass transport and active zone utilization, achieving around 99% pollutant removal. This work highlights a GB engineering route to efficient and durable electrocatalysts for water treatment.
Gu et al. (Thu,) studied this question.