Yang Xiaolong, Wang Ying, Wang Xian, Mei Bingbao, Luo Ergui, Li Yang, Meng Qinglei, Jin Zhao, Jiang Zheng, Liu Changpeng, Ge Junjie, Xing Wei
State Key Laboratory of Electroanalytic Chemistry, Jilin Province Key Laboratory of Low Carbon Chemistry Power, Institution Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, 130022, P. R. China.
School of Applied Chemistry and Engineering, University of Science and Technology of China, Hefei, 230026, P. R. China.
Angew Chem Int Ed Engl. 2021 Dec 6;60(50):26177-26183. doi: 10.1002/anie.202110900. Epub 2021 Nov 5.
Proton-exchange membrane fuel cells (PEMFCs) are limited by their extreme sensitivity to trace-level CO impurities, thus setting a strict requirement for H purity and excluding the possibility to directly use cheap crude hydrogen as fuel. Herein, we report a proof-of-concept study, in which a novel catalyst comprising both Ir particles and Ir single-atom sites (Ir @Ir -N-C) addresses the CO poisoning issue. The Ir single-atom sites are found not only to be good CO oxidizing sites, but also excel in scavenging the CO molecules adsorbed on Ir particles in close proximity, thereby enabling the Ir particles to reserve partial active sites towards H oxidation. The interplay between Ir nanoparticles and Ir single-atom centers confers the catalyst with both excellent H oxidation activity (1.19 W cm ) and excellent CO electro-oxidation activity (85 mW cm ) in PEMFCs; the catalyst also tolerates CO in H /CO mixture gas at a level that is two times better than that of the current best PtRu/C catalyst.
质子交换膜燃料电池（PEMFC）对痕量一氧化碳杂质极为敏感，这限制了其应用，因此对氢气纯度提出了严格要求，排除了直接使用廉价粗氢作为燃料的可能性。在此，我们报告一项概念验证研究，其中一种包含铱颗粒和铱单原子位点的新型催化剂（Ir@Ir-N-C）解决了一氧化碳中毒问题。研究发现，铱单原子位点不仅是良好的一氧化碳氧化位点，而且在清除紧邻铱颗粒吸附的一氧化碳分子方面表现出色，从而使铱颗粒能够保留部分用于氢氧化的活性位点。铱纳米颗粒与铱单原子中心之间的相互作用赋予该催化剂在质子交换膜燃料电池中出色的氢氧化活性（1.19 W cm）和出色的一氧化碳电氧化活性（85 mW cm）；该催化剂还能耐受氢/一氧化碳混合气体中的一氧化碳，耐受水平比目前最佳的PtRu/C催化剂高一倍。
