Yang Deren, Zhang Chunyang, Qin Yufeng, Yue Yang, Liu Yubo, Shi Xiaoyun, Hua Kang, An Xuemin, Jin Louyu, Zhang Yipeng, Zuo Shouwei, Tan Aidong, Liu Jianguo
Beijing Laboratory of New Energy Storage Technology, Institute of Energy Power Innovation, North China Electric Power University, 2 Beinong Road, Beijing, 102206, P. R. China.
Beijing Synchrotron Radiation Facility, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing, 100049, P. R. China.
Nat Commun. 2025 Aug 6;16(1):7236. doi: 10.1038/s41467-025-62665-2.
Both commercial and laboratory-synthesized IrO catalysts typically possess rutile-type structures with multiple facets. Theoretical results predict the (101) facet is the most energetically favorable for oxygen evolution reaction owing to its lowest energy barrier. Achieving monolayer thickness while exposing this desired facet is a significant opportunity for IrO. Herein, we develop an ammonia-induced facet engineering for the synthesis of single-faceted IrO(101) monolayer. It achieves 230 mV overpotential at 10 mA cm in a three-electrode system and 1.70 V at 2 A cm in a proton exchange membrane (PEM) electrolyzer. Though facet engineering primarily contributes to modulating the intrinsic activity rather than stability, single-faceted IrO monolayer performs over 10,000-hour stability at constant 1.5 A cm (3.95 mV kh decay) and 1000-hour stability at 0.2 mg cm under fluctuating conditions. This work proposes that ammonia-induced facet engineering of IrO monolayer enables facet-dependent oxygen evolution reaction (OER) performance and high stability in industrial-scale PEM electrolysis.
商业合成和实验室合成的氧化铱（IrO）催化剂通常具有多晶面的金红石型结构。理论结果预测，（101）晶面由于其最低的能垒，在析氧反应中在能量上最为有利。对于氧化铱来说，在暴露这一所需晶面的同时实现单层厚度是一个重大机遇。在此，我们开发了一种氨诱导的晶面工程方法来合成单面的IrO(101)单层。在三电极系统中，它在10 mA cm²时实现了230 mV的过电位，在质子交换膜（PEM）电解槽中，在2 A cm²时实现了1.70 V的过电位。尽管晶面工程主要有助于调节本征活性而非稳定性，但单面的IrO单层在1.5 A cm²恒定电流下表现出超过10000小时的稳定性（每千小时衰减3.95 mV），在波动条件下，在0.2 mg cm²时具有1000小时的稳定性。这项工作表明，氨诱导的IrO单层晶面工程能够实现依赖于晶面的析氧反应（OER）性能，并在工业规模的PEM电解中具有高稳定性。
