ABSTRACT Iridium‐based catalysts for the acidic oxygen evolution reaction (OER) predominantly follow the adsorbate evolution mechanism (AEM), with their intrinsic activity limited by sluggish proton‐transfer kinetics. Based on this, a strategy is proposed involving the construction of a discontinuous WO x interlayer incorporating isolated W single atoms and amorphous WO x clusters on supported Ir‐based catalysts. The optimized Ir/W‐TiN catalyst achieves current densities of 100 mA cm −2 at remarkably low overpotentials of 293 mV. Leveraging the non‐lattice oxygen from the amorphous WO x , this design promotes a shift in the reaction pathway from the conventional AEM to an interface non‐lattice oxygen‐assisted deprotonation mechanism (IOADM), simultaneously enhancing both activity and stability. The incorporation of W species facilitates the formation of oxygen vacancies and a hydrogen‐bond network, which lowers the reaction energy barrier and accelerates deprotonation kinetics. In a proton exchange membrane water electrolyzer, the membrane electrode assembly with the Ir/W‐TiN anode exhibits a high current density exceeding 2.2 A cm −2 at 1.8 V. Furthermore, with a low Ir loading of 0.2 mgIr cm −2 , it demonstrates excellent durability, maintaining stable operation for 2000 h at 1.0 A cm −2 . This work provides new mechanistic insights for designing highly efficient, stable, and low‐Ir‐loaded anode catalysts via interface engineering.
Fang et al. (Mon,) studied this question.