Highly Interdiffused W-Ir Interfaces Enhances Acidic Oxygen Evolution

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-IrO₂/WO₃ 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 IrO₂ surface. Transient potential scanning (TPS) measurements further confirm that this highly interdiffused interface significantly enhances interfacial charge transfer rates.