Duan Xingjun, Yu Xiangtao, Yang Tao, Wang Enhui, Hou Yanglong, Hou Xinmei
Institute for Carbon Neutrality, University of Science and Technology Beijing, Beijing, 100083, China.
Collaborative Innovation Center of Steel Technology, University of Science and Technology Beijing, Beijing, 100083, China.
Small. 2025 Jun;21(24):e2503136. doi: 10.1002/smll.202503136. Epub 2025 May 8.
Ir in a lower oxidation state exhibits superior intrinsic activity for oxygen evolution reaction (OER) due to its low Ir-O connectivity in alkaline media. However, it is more prone to being oxidized to a high oxidation state and dissolving inactivation during the OER process. Herein, single-atom Ir in a lower oxidation state is dispersed on a sea urchin-like FeNi-based spinel support (NiFeO) possessing super-hydrophilicity and super-aerophobicity. The as-prepared Ir/NiFeO, loading of only 0.087 mg cm Ir element, shows 196 mV overpotential at 10 mA cm, and it can work stably up to 400 h at 200 mA cm in 1 m KOH solution. The OER performance of Ir/NiFeO surpasses that of commercial IrO catalysts and most currently reported Ir/Ru-based single-atom catalysts (SACs), which can be attributed to Fe in the support acting as an electron reservoir, maintaining the lower oxidation state of single-atom Ir with high activity and stability during the OER process. Furthermore, the catalytic interface exhibits both super-hydrophilicity and super-aerophobicity, which not only facilitates electron-ion coupling transport but also promotes the rapid removal of generated oxygen bubbles.
处于较低氧化态的铱由于在碱性介质中其低铱-氧连接性而对析氧反应（OER）表现出优异的本征活性。然而，在OER过程中它更容易被氧化到高氧化态并溶解失活。在此，处于较低氧化态的单原子铱分散在具有超亲水性和超疏气性的海胆状铁镍基尖晶石载体（NiFeO）上。所制备的Ir/NiFeO，铱元素负载量仅为0.087 mg cm，在10 mA cm时显示出196 mV的过电位，并且在1 m KOH溶液中于200 mA cm下可稳定工作长达400小时。Ir/NiFeO的OER性能超过了商业IrO催化剂以及目前报道的大多数铱/钌基单原子催化剂（SACs），这可归因于载体中的铁作为电子库，在OER过程中保持单原子铱的较低氧化态并具有高活性和稳定性。此外，催化界面同时具有超亲水性和超疏气性，这不仅有利于电子-离子耦合传输，还促进了生成的氧气气泡的快速去除。
