Tian Guo, Liu Xinyan, Zhang Chenxi, Fan Xiaoyu, Xiong Hao, Chen Xiao, Li Zhengwen, Yan Binhang, Zhang Lan, Wang Ning, Peng Hong-Jie, Wei Fei
Beijing Key Laboratory of Green Chemical Reaction Engineering and Technology, Department of Chemical Engineering, Tsinghua University, Beijing, 100084, China.
Institute of Fundamental and Frontier Sciences, University of Electronic Science and Technology of China, Chengdu, 611731, Sichuan, China.
Nat Commun. 2022 Sep 22;13(1):5567. doi: 10.1038/s41467-022-33217-9.
Spontaneous monodispersion of reducible active species (e.g., Fe, Co) and their stabilization in reductive atmospheres remain a key challenge in catalytic syngas chemistry. In this study, we present a series of catalysts including spontaneously monodispersed and enriched Fe on ZnCrO. Deep investigation shows remarkable performance in the syngas-to-aromatic reaction only when monodispersed Fe coupled with a H-ZSM-5 zeolite. Monodispersed Fe increases the turnover frequency from 0.14 to 0.48 s without sacrificing the record high selectivity of total aromatics (80-90%) at a single pass. The increased activity is ascribed to more efficient activation of CO and H at oxygen vacancy nearest to the isolated Fe site and the prevention of carbide formation. Atomic precise characterization and theoretical calculations shed light on the origin and implications of spontaneous Fe monodispersion, which provide guidance to the design of next-generation catalyst for upgrading small molecules to synthetic fuels and chemicals.
可还原活性物种（如铁、钴）的自发单分散及其在还原气氛中的稳定化仍然是催化合成气化学中的一个关键挑战。在本研究中，我们展示了一系列催化剂，包括在ZnCrO上自发单分散和富集的铁。深入研究表明，只有当单分散的铁与H-ZSM-5沸石耦合时，在合成气制芳烃反应中才具有显著性能。单分散的铁将周转频率从0.14提高到0.48 s，同时在单程中不牺牲总芳烃创纪录的高选择性（80-90%）。活性的提高归因于在最接近孤立铁位点的氧空位处对CO和H的更有效活化以及对碳化物形成的抑制。原子精确表征和理论计算揭示了铁自发单分散的起源和意义，为设计将小分子升级为合成燃料和化学品的下一代催化剂提供了指导。
