Self‐Healing Iridium‐Doped Manganese Oxide for Boosting Stability of Acidic Oxygen Evolution

Abstract Developing low‐iridium electrocatalysts combined with high efficiency and longevity for oxygen evolution reaction (OER) in proton exchange membrane (PEM) water electrolysis remains challenging in the hydrogen economy. Here, an anodic electro‐oxidation approach is reported to fabricate iridium (Ir) dope MnO₂ gas diffusion electrodes, which exhibited remarkable stability of over 1650 h at 100 mA cm⁻² with a record‐high stability number of 2.9 × 10⁸ by considering Ir leaching. The optimized catalyst with a low Ir loading of ≈0.3 mg cm⁻² achieved stable operation at 1.0 A cm⁻² in the PEM electrolyzer. The investigation reveals that the generation of high‐valence Ir within MnO₂ optimizes oxygen desorption and thereby boosts activity. Furthermore, MnO₂ provides a platform that enables the oxidation and deposition of leached ions, initiating a self‐healing mechanism that extends the operational lifetime of catalyst. This paves an effective way toward addressing the dissolution issues encountered by OER catalysts in acidic electrolytes.