Du Jian, Ding Yunxuan, Guo Yu, Sun Licheng, Li Fei
State Key Laboratory of Fine Chemicals, DUT-KTH Joint Education and Research Centre on Molecular Devices, Dalian University of Technology, Dalian 116024, China.
Center of Artificial Photosynthesis for Solar Fuels and Department of Chemistry, School of Science, Westlake University, Hangzhou 310024, China.
iScience. 2023 Jul 16;26(8):107339. doi: 10.1016/j.isci.2023.107339. eCollection 2023 Aug 18.
Carbon-supported iron-cobalt bimetallic electrocatalysts usually exhibit robust catalytic activity toward the oxygen evolution reaction (OER). However, the spatial isolation of Fe species at atomic level on cobalt-carbon solid remains a great challenge for practical catalytic applications in the OER. Here, we report the fabrication of CoFe bimetal porous carbon electrocatalysts by pyrolysis of molecularly defined iron complexes such as FePc (Pc = phthalocyanine) and Fe(acac) pre-encapsulated in the cavities of zeolitic imidazolate framework (ZIF)-67. With this unique strategy, high-loading atomic Fe nanoclusters (Fe-ACs) and Fe single atoms (Fe-SAs) were supported on Co/NC hybrids relying on the size of the molecular Fe precursors. The former exhibited superior OER performance to the single Fe atom-decorated Co/NC, as well as other ZIF-67-derived electrocatalysts. Theoretical modulation suggests Co as the OER active site for Fe-ACs@Co/NC at the -formed FeOOH-ACs/CoO interface, while Fe was proposed as the active site for Fe-SAs@Co/NC.
碳负载的铁钴双金属电催化剂通常对析氧反应（OER）表现出强大的催化活性。然而，在钴碳固体上实现原子级别的铁物种空间隔离对于OER的实际催化应用而言仍然是一个巨大的挑战。在此，我们报道了通过热解分子定义的铁配合物（如封装在沸石咪唑酯骨架（ZIF）-67孔穴中的FePc（Pc = 酞菁）和Fe(acac)）来制备CoFe双金属多孔碳电催化剂。通过这种独特的策略，基于分子铁前驱体的尺寸，高负载的原子铁纳米团簇（Fe-ACs）和铁单原子（Fe-SAs）负载在Co/NC杂化物上。前者表现出比单原子铁修饰的Co/NC以及其他ZIF-67衍生的电催化剂更优异的OER性能。理论调控表明，在形成的FeOOH-ACs/CoO界面处，Co是Fe-ACs@Co/NC的OER活性位点，而Fe被认为是Fe-SAs@Co/NC的活性位点。
