Sulfur‐Doped IrO 2 Enable Pathway Switch to Lattice Oxygen Mechanism with Enhanced Stability for Low Iridium PEM Water Electrolysis

作者：Chenlu Yang, Yanping Zhu, Fengru Zhang, Longping Yao, Yihe Chen, Tenglong Lu, Qixuan Li, Jun Li, Guo‐Liang Wang, Qingqing Cheng, Hui Yang · 发表于：Advanced Materials · 年份：2025 · DOI：10.1002/adma.202507560 · 被引用次数：51 · 研究领域：Fuel Cells and Related Materials、Electrocatalysts for Energy Conversion、Advanced Memory and Neural Computing

Abstract Achieving high activity and stability while minimizing Ir usage poses a significant challenge in the industrialization of proton exchange membrane water electrolysis (PEMWE). Herein we report a sulfur‐doping strategy that enables the OER pathway on IrO 2 nanoparticles (IrO 2 /S) to switch from conventional adsorption evolution mechanism (AEM) to lattice oxygen mechanism (LOM) while maintaining Ir─O bond stability, thus achieving a significant enhancement in both intrinsic activity and durability. Advanced spectroscopies and theoretical calculations reveal that the Ir─S coordination motif within the lattice increases the electron density of the Ir center and enhances Ir─O covalency, thus triggering the LOM pathway. Importantly, the lattice distortion and unsaturated Ir─O coordination within the IrO 2 /S generate the oxygen nonbonding state that acts as an electron sacrificial agent to preserve Ir─O bonds upon the LOM‐dominated OER process. As a result, PEMWE integrated with such IrO 2 /S electrocatalyst delivers a low cell voltage (1.769 V at 2.0 A cm −2 ) and long‐term stability (16.6 µV h⁻¹ over 1000 h@1.0 A cm⁻ 2 ) while dramatically reducing Ir usage from 1.0 to 0.3 mg cm −2 . This work establishes S doping as a viable strategy to trigger LOM and stabilize lattice oxygen redox in Ir‐based catalysts, opening a new avenue for low‐Ir PEMWEs.