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Mechanistic differences between methanol and dimethyl ether in zeolite-catalyzed hydrocarbon synthesis

Kirchberger, Felix M.; Liu, Yue; Plessow, Philipp N. ORCID iD icon; Tonigold, Markus; Studt, Felix; Sanchez-Sanchez, Maricruz; Lercher, Johannes A.

Abstract:

Water influences critically the kinetics of the autocatalytic conversion of methanol to hydrocarbons in acid zeolites. At very low conversions but otherwise typical reaction conditions, the initiation of the reaction is delayed in presence of H$_{2}$O. In absence of hydrocarbons, the main reactions are the methanol and dimethyl ether (DME) interconversion and the formation of a C$_{1}$ reactive mixture—which in turn initiates the formation of first hydrocarbons in the zeolite pores. We conclude that the dominant reactions for the formation of a reactive C$_{1}$ pool at this stage involve hydrogen transfer from both MeOH and DME to surface methoxy groups, leading to methane and formaldehyde in a 1:1 stoichiometry. While formaldehyde reacts further to other C$_{1}$ intermediates and initiates the formation of first C–C bonds, CH$_{4}$ is not reacting. The hydride transfer to methoxy groups is the rate-determining step in the initiation of the conversion of methanol and DME to hydrocarbons. Thus, CH$_{4}$ formation rates at very low conversions, i.e., in the initiation stage before autocatalysis starts, are used to gauge the formation rates of first hydrocarbons. ... mehr


Verlagsausgabe §
DOI: 10.5445/IR/1000142661
Veröffentlicht am 03.02.2022
Originalveröffentlichung
DOI: 10.1073/pnas.2103840119
Scopus
Zitationen: 16
Web of Science
Zitationen: 14
Dimensions
Zitationen: 17
Cover der Publikation
Zugehörige Institution(en) am KIT Institut für Katalyseforschung und -technologie (IKFT)
Institut für Technische Chemie und Polymerchemie (ITCP)
Publikationstyp Zeitschriftenaufsatz
Publikationsjahr 2022
Sprache Englisch
Identifikator ISSN: 0027-8424, 1091-6490
KITopen-ID: 1000142661
HGF-Programm 38.03.02 (POF IV, LK 01) Power-based Fuels and Chemicals
Erschienen in Proceedings of the National Academy of Sciences of the United States of America
Verlag National Academy of Sciences
Band 119
Heft 4
Seiten Art.-Nr. e2103840119
Vorab online veröffentlicht am 04.11.2021
Schlagwörter methanol to hydrocarbons; H-ZSM-5; formaldehyde; hydrogen transfer
Nachgewiesen in Scopus
Dimensions
Web of Science
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