Quantifying the Hydration-Dependent Dynamics of Cu Migration and Activity in Zeolite Omega for the Partial Oxidation of Methane.

Autor: Wieser J; Department of Chemistry and Applied Biosciences, Institute for Chemical and Bioengineering, ETH Zurich, 8093, Zürich, Switzerland., Wardecki D; Institute of Experimental Physics, Faculty of Physics, University of Warsaw, 02-093, Warsaw, Poland., Fischer JWA; Department of Chemistry and Applied Biosciences, Institute of Molecular Physical Science, ETH Zurich, 8093, Zürich, Switzerland., Newton MA; Department of Chemistry and Applied Biosciences, Institute for Chemical and Bioengineering, ETH Zurich, 8093, Zürich, Switzerland.; Department of Structure and Dynamics in Catalysis, J. Heyrovsky Institute of Physical Chemistry, Dolejškova 2155/3, 182 23, Prague 8, Czech Republic., Dejoie C; ID22, European Synchrotron Radiation Facility, 38043, Grenoble, France., Knorpp AJ; Department of Chemistry and Applied Biosciences, Institute for Chemical and Bioengineering, ETH Zurich, 8093, Zürich, Switzerland., Hansen TC; Institut Laue-Langevin, 71 Avenue des Martyrs, 38000, Grenoble, France., Jeschke G; Department of Chemistry and Applied Biosciences, Institute of Molecular Physical Science, ETH Zurich, 8093, Zürich, Switzerland., Rzepka P; Department of Chemistry and Applied Biosciences, Institute for Chemical and Bioengineering, ETH Zurich, 8093, Zürich, Switzerland.; Department of Structure and Dynamics in Catalysis, J. Heyrovsky Institute of Physical Chemistry, Dolejškova 2155/3, 182 23, Prague 8, Czech Republic.; Center for Energy and Environmental Science, Paul Scherrer Institute (PSI), 5232, Villigen, Switzerland., van Bokhoven JA; Department of Chemistry and Applied Biosciences, Institute for Chemical and Bioengineering, ETH Zurich, 8093, Zürich, Switzerland.; Center for Energy and Environmental Science, Paul Scherrer Institute (PSI), 5232, Villigen, Switzerland.
Jazyk: angličtina
Zdroj: Angewandte Chemie (International ed. in English) [Angew Chem Int Ed Engl] 2024 Dec 02; Vol. 63 (49), pp. e202407395. Date of Electronic Publication: 2024 Nov 02.
DOI: 10.1002/anie.202407395
Abstrakt: Copper-exchanged zeolite omega (Cu-omega) is a potent material for the selective conversion of methane-to-methanol (MtM) via the oxygen looping approach. However, its performance exhibits substantial variation depending on the operational conditions. Under an isothermal temperature regime, Cu-omega demonstrates subdued activity below 230 °C, but experiences a remarkable increase in activity at 290 °C. Applying a high-temperature activation protocol at 450 °C causes a rapid deactivation of the material. This behavioral divergence is investigated by combining reactivity studies, neutron diffraction and in situ high-resolution anomalous X-ray powder diffraction (HR-AXRPD), as well as electron paramagnetic resonance spectroscopy, to reveal that the migration of Cu throughout the framework is the primary cause of these behaviors, which in turn is predominantly governed by the degree of hydration of the system. This work suggests that control over the Cu migration throughout the zeolite framework may be harnessed to significantly increase the activity of Cu-omega by generating more active sites for the MtM conversion. These results underscore the power of in situ HR-AXRPD for unraveling the behavior of materials under reaction conditions and suggest that a re-evaluation of Cu-zeolites priorly deemed inactive for the MtM conversion across a broader range of conditions and looping protocols may be warranted.
(© 2024 The Authors. Angewandte Chemie International Edition published by Wiley-VCH GmbH.)
Databáze: MEDLINE
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