Fluorine‐Doped RuO ₂ Anchored on TiO ₂ via Proton‐Assisted Adsorption Evolution for Efficient and Stable Oxygen Evolution Reaction in Acid

Abstract

ABSTRACT Although RuO 2 theoretically has superior oxygen evolution reaction (OER) activity and a relatively lower price than IrO 2 , 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 RuO 2 ‐based electrocatalysts for OER. This study developed an F‐doped RuO 2 loaded on TiO 2 (F‐RuO 2 @TiO 2 ) to construct a Ru–O–Ti interface platform for electronegativity‐mediated charge redistribution. F‐RuO 2 @TiO 2 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‐RuO 2 @TiO 2 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 TiO 2 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 RuO 2 .