Acid‐Stable Ruthenium‐Based Solid Solution for Oxygen Evolution in Proton Exchange Membrane Electrolyzers
Zexuan Wu, Ligang Wang, Yanqiang Kong, Qiwen Zhang, Shilin Ling, Lei Chen, Weijia Wang, Xiaoyan Luo, Lijun Yang, Xiaoze Du, Feng Hu, Shengjie Peng, Y. Yang
Abstract
Abstract Proton exchange membrane (PEM) water electrolysis offers a promising route for green hydrogen production, yet balancing catalytic activity and durability remains challenging for oxygen evolution reaction (OER) catalysts in acid, particularly for non‐Ir‐based catalysts. Herein, we develop a template‐guided strategy to synthesize the metal–organic framework (MOF)‐derived RuZrCoCrCeO 2 solid solution with tunable multi‐metal heteroatom regulation. The catalyst demonstrates outstanding acidic OER performance, requiring only 179 mV overpotential to achieve 10 mA cm geo −2 and remarkable durability over 1500 h at 50 mA cm geo −2 with a negligible decay of 30.67 µV h −1 . An “electronic buffer” effect facilitates electron transfer from atomically dispersed Zr to Ru, forming asymmetric Ru─O─Zr bonds with enhanced metal–oxygen covalency, thereby preventing excessive oxidation of Ru species. A vicinal deprotonation mechanism was proposed, where lattice oxygen assists *OOH deprotonation with a lower energy barrier on Ru─O─M sites. A PEM electrolyzer with low Ru loading (0.37 mg Ru cm −2 ) achieves an industrial‐level current density of 1 A cm −2 at 1.66 V, corresponding to a low hydrogen cost of US$0.89 kg −1 below the US DOE target (US$2 per kg of H 2 ), and operates stably for 600 h at 200 mA cm geo −2 , demonstrating its practical potential for scalable, Ir‐free PEM electrolyzers.