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Understanding the Preparation and Reactivity of Mo/ZSM‐5 Methane Dehydroaromatization Catalysts
Author(s) -
Liu Yujie,
Zhang Hao,
Wijpkema Alexandra S. G.,
Coumans Ferdy J. A. G.,
Meng Lingqian,
Uslamin Evgeny A.,
Longo Alessandro,
Hensen Emiel J. M.,
Kosinov Nikolay
Publication year - 2022
Publication title -
chemistry – a european journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.687
H-Index - 242
eISSN - 1521-3765
pISSN - 0947-6539
DOI - 10.1002/chem.202103894
Subject(s) - catalysis , methanation , chemistry , methane , benzene , coke , hydrocarbon , molybdenum , zeolite , zsm 5 , inorganic chemistry , induction period , decomposition , photochemistry , organic chemistry
Methane dehydroaromatization is a promising reaction for the direct conversion of methane to liquid hydrocarbons. The active sites and the mechanism of this reaction remain controversial. This work is focused on the operando X‐ray absorption near edge structure spectroscopy analysis of conventional Mo/ZSM‐5 catalysts during their whole lifetime. Complemented by other characterization techniques, we derived spectroscopic descriptors of molybdenum precursor decomposition and its exchange with zeolite Brønsted acid sites. We found that the reduction of Mo‐species proceeds in two steps and the active sites are of similar nature, regardless of the Mo content. Furthermore, the ZSM‐5 unit cell contracts at the beginning of the reaction, which coincides with benzene formation and it is likely related to the formation of hydrocarbon pool intermediates. Finally, although reductive regeneration of used catalysts via methanation is less effective as compared to combustion of coke, it does not affect the structure of the catalysts.