Zexuan Wu, Yanxiao Wan, Chenxuan Xie, Kaiyang Li, Xiaohong Chen, Lu Yu, Lijun Yang, Xiaoze Du, Yanqiang Kong, Chao Su, Yongping Yang
Proton exchange membrane water electrolysis (PEMWE) is critical for renewable energy integration, yet it remains constrained by costly Ir-based oxygen evolution reaction (OER) catalysts and the activity-stability trade-off of Ru-based alternatives, which suffer from lattice oxygen mechanism (LOM)-induced degradation. Herein, we report an Ir and Mn co-doped Ru/RuO2 heterostructure (IM-Ru/RuO2) synthesized via a metal-organic framework sacrificial template strategy. In this structure, trace Ir anchors lattice oxygen to suppress LOM, while Mn donates electrons to lower Ru oxidation state through asymmetric Ru-O-Mn motifs. Benefiting from this synergistic effect, IM-Ru/RuO2 exhibits an overpotential of 182 mV at 10 mA cm-2 and stability over 600 h. In situ differential electrochemical mass spectroscopy, infrared spectroscopy, and theoretical calculations confirm that the OER proceeds predominantly through an enhanced adsorbate evolution mechanism instead of the detrimental LOM pathway. When integrated into a PEMWE device with ultralow noble-metal loadings (0.36 mgRu cm-2 and 0.024 mgIr cm-2), the catalyst delivers 1.640 V at 1 A cm-2, operates stably for 450 h, and enables a hydrogen production cost of US$0.88 kg-1-below the U.S. DOE 2031 targets. This work establishes a versatile electronic and structural engineering strategy for Ru-based catalysts to advance PEMWE toward large-scale renewable hydrogen production.