Fluorine-Doped RuO₂ Anchored on TiO₂ via Proton-Assisted Adsorption Evolution for Efficient and Stable Oxygen...

Although RuO₂ theoretically has superior oxygen evolution reaction (OER) activity and a relatively lower price than IrO₂, balancing its activity and stability remains a significant challenge. The electronic structure of Ru centers plays a critical role in balancing the activity and durability of RuO₂-based electrocatalysts for OER. This study developed an F-doped RuO₂ loaded on TiO₂ (F-RuO₂@TiO₂) to construct a Ru-O-Ti interface platform for electronegativity-mediated charge redistribution. F-RuO₂@TiO₂ exhibited excellent OER activity and superior durability, operating stably for 660 h and 253 h at 100 and 200 mA cm^-2, respectively. A proton exchange membrane water electrolyzer assembled using F-RuO₂@TiO₂ required only 1.57 and 1.68 V at 0.5 and 1 A cm^-2, respectively, and operated stably for 300 and 100 h, respectively. Both experimental and theoretical calculations showed that the high electronegativity of F enhances the Ru-O covalency, thereby accelerating the deprotonation of *OOH through the proton-assisted adsorption evolution mechanism (PA-AEM). Simultaneously, the dynamic charge redistribution established between Ru-O-Ti allowed TiO₂ to buffer charge fluctuations at Ru sites, thus further effectively mitigating over-oxidation. These findings underscore the importance of electronegativity-regulated proton-transfer kinetics for stabilizing RuO₂.