Highly Interdiffused W‐Ir Interfaces Enhances Acidic Oxygen Evolution

ABSTRACT The application of proton exchange membrane water electrolysis (PEMWE) technology heavily relies on breakthroughs in oxygen evolution reaction (OER) catalyst performance. Traditional iridium‐based catalysts suffer from bottlenecks such as low atomic utilization and insufficient long‐term operational stability, limiting their practical application potential. This study constructed a catalyst model by introducing a non‐precious metal atom (W) into the iridium dioxide lattice for atomic‐level anchoring, forming a highly interdiffused interface structure. This structural optimization significantly enhanced reaction kinetics, enabling the catalyst to achieve outstanding catalytic activity at a current density of 10 mA cm ^{− 2} with an overpotential of only 204 mV. Notably, after 1000 h of operation, its performance degradation rate was only 0.02 mV h ^{− 1} . In a PEMWE system, W‐IrO ₂ /WO ₃ operated continuously at 1.7 V and 1.05 A cm ^{− 2} for 720 h without significant decay. Density functional theory (DFT) calculations reveal that tungsten ions at the highly interdiffused interface effectively lower the energy barrier for oxygen evolution reactions on the IrO ₂ surface. Transient potential scanning (TPS) measurements further confirm that this highly interdiffused interface significantly enhances interfacial charge transfer rates.