Exploring the Impact of Active Site Structure on the Conversion of Methane to Methanol in Cu-Exchanged Zeolites.

Autor: Göltl F; The University of Arizona, Department of Biosystems Engineering, 1177, E 4th St., 85719, Tucson, AZ, United States.; The University of Wisconsin - Madison, Department of Chemical and Biological Engineering, 1415 Engineering Drive, 53706, Madison, WI, United States., Bhandari S; The University of Wisconsin - Madison, Department of Chemical and Biological Engineering, 1415 Engineering Drive, 53706, Madison, WI, United States., Lebrón-Rodríguez EA; The University of Wisconsin - Madison, Department of Chemical and Biological Engineering, 1415 Engineering Drive, 53706, Madison, WI, United States., Gold JI; The University of Wisconsin - Madison, Department of Chemical and Biological Engineering, 1415 Engineering Drive, 53706, Madison, WI, United States., Hutton DJ; The University of Arizona, Department of Biosystems Engineering, 1177, E 4th St., 85719, Tucson, AZ, United States., Zones SI; Chevron Energy Technology Company, Richmond, CA 94804, United States., Hermans I; The University of Wisconsin - Madison, Department of Chemical and Biological Engineering, 1415 Engineering Drive, 53706, Madison, WI, United States.; The University of Wisconsin - Madison, Department of Chemistry, 1101 University Avenue, 53706, Madison, WI, United States., Dumesic JA; The University of Wisconsin - Madison, Department of Chemical and Biological Engineering, 1415 Engineering Drive, 53706, Madison, WI, United States., Mavrikakis M; The University of Wisconsin - Madison, Department of Chemical and Biological Engineering, 1415 Engineering Drive, 53706, Madison, WI, United States.
Jazyk: angličtina
Zdroj: Angewandte Chemie (International ed. in English) [Angew Chem Int Ed Engl] 2024 Jun 03; Vol. 63 (23), pp. e202403179. Date of Electronic Publication: 2024 Apr 30.
DOI: 10.1002/anie.202403179
Abstrakt: In the past, Cu-oxo or -hydroxy clusters hosted in zeolites have been suggested to enable the selective conversion of methane to methanol, but the impact of the active site's stoichiometry and structure on methanol production is still poorly understood. Herein, we apply theoretical modeling in conjunction with experiments to study the impact of these two factors on partial methane oxidation in the Cu-exchanged zeolite SSZ-13. Phase diagrams developed from first-principles suggest that Cu-hydroxy or Cu-oxo dimers are stabilized when O 2 or N 2 O are used to activate the catalyst, respectively. We confirm these predictions experimentally and determine that in a stepwise conversion process, Cu-oxo dimers can convert twice as much methane to methanol compared to Cu-hydroxyl dimers. Our theoretical models rationalize how Cu-di-oxo dimers can convert up to two methane molecules to methanol, while Cu-di-hydroxyl dimers can convert only one methane molecule to methanol per catalytic cycle. These findings imply that in Cu clusters, at least one oxo group or two hydroxyl groups are needed to convert one methane molecule to methanol per cycle. This simple structure-activity relationship allows to intuitively understand the potential of small oxygenated or hydroxylated transition metal clusters to convert methane to methanol.
(© 2024 The Authors. Angewandte Chemie International Edition published by Wiley-VCH GmbH.)
Databáze: MEDLINE
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