Dynamic Oxygen Species Evolution Boosts Acidic Water Oxidation on W‐Doped RuO ₂

RuO 2 undergoes severe structural degradation during acidic oxygen evolution reaction (OER) under high anodic potentials, including Ru oxidation into high‐valence species and lattice oxygen depletion, limiting its practical application. Tungsten, featuring strong oxophilicity and multiple valence states, effectively modulates the electronic structure of Ru sites due to electronegativity difference between W n+ and Ru 4+ , stabilizing both Ru centers and lattice oxygen. Accordingly, a W‐doped RuO 2 catalyst (W 0.05 Ru 0.95 O 2 , WRO) is developed to achieve dynamic oxygen species evolution via regulated lattice oxygen diffusion kinetics. The optimized oxygen diffusion coefficient (2.11 × 10 −15 cm 2 s −1 ) ensures a balance between oxygen vacancy replenishment and lattice oxygen retention. X‐ray absorption spectroscopy and tetramethylammonium probing reveal that WRO undergoes LOM‐dominated dynamic reconstruction at the initial stage, transforming from low‐coordination defective sites to a stable six‐coordinated Ru‐O framework. Consequently, WRO exhibits high activity with overpotential of 200 mV at 10 mA cm −2 in a three‐electrode system and promising durability of >400 h at 100 mA cm −2 in a two‐electrode system. A PEM electrolyzer with WRO as the anode operates stably for over 130 h at 200 mA cm −2 . This work demonstrates that tuning oxygen diffusion kinetics enables dynamic coordination regulation, offering new insights for designing robust acidic OER catalysts.