Cracking the Code of RuO ₂ Corrosion: A Theoretical Exploration of Potential‐Driven Switches Between Oxidative and Reductive Pathways

Ruthenium dioxide (RuO 2 ) is a benchmark catalyst for the oxygen evolution reaction (OER) in acidic media but suffers from slow dissolution under operating conditions, limiting its long‐term durability. Here, density functional theory combined with the computational hydrogen electrode model is employed to elucidate the atomistic mechanisms governing RuO 2 surface corrosion across a relevant potential window from 0 to 1.5 V standard hydrogen electrode (SHE) . The study reveals a potential‐dependent switch in dissolution pathways: at anodic potentials above 1.21 V SHE , direct oxidative dissolution leads to soluble RuO 4 , whereas at lower potentials, coupled proton–electron transfer reactions drive the formation of soluble hydroxylated species, specifically Ru(OH) 4 and RuO 2 (OH) 2 . Key surface intermediates act as energetic basins, regulating transient dissolution during potential cycling and shutdown. Furthermore, it is shown that doping RuO 2 with W, Ti, or Ir shifts the onset potentials for these corrosion pathways, enhancing surface stability by widening the potential window where the materials are stable. These insights advance the mechanistic understanding of RuO 2 degradation and support rational strategies for designing durable OER catalysts in acidic water‐splitting technologies.