Innenrücktitelbild: Rationalizing Acidic Oxygen Evolution Reaction over IrO2: Essential Role of Hydronium Cation (Angew. Chem. 48/2024)

Acid environment was found to play a critical role in regulating the catalytic behavior of IrO2 during the oxygen evolution reaction (OER). As demonstrated by Jingguang G. Chen, Ping Liu et al. in their Research Article (e202409526), the presence of hydronium cation (H3O+) introduces an internal electric field at the interface. It allows selective bond‐tuning of the reaction intermediates and formation of partial surface hydroxylation under the operational conditions, which actively catalyzed the OER.