Статья

Stability of Zeolites in Hot Liquid Water

Ryan M. RavenelleSchool of Chemical & Biomolecular Engineering, Georgia Institute of Technology, 311 Ferst Drive NW, Atlanta, Georgia 30332-0100, United States, Department of Chemistry and Catalysis Research Center, Technische Universität München, Lichtenbergstraβe 4, 85747 Garching, Germany, Institute for Chemical and Bioengineering, ETH Zurich, 8093 Zurich, Switzerland, and Paul Scherrer Institute, 5232 Villigen, SwitzerlandFlorian SchüβlerSchool of Chemical & Biomolecular Engineering, Georgia Institute of Technology, 311 Ferst Drive NW, Atlanta, Georgia 30332-0100, United States, Department of Chemistry and Catalysis Research Center, Technische Universität München, Lichtenbergstraβe 4, 85747 Garching, Germany, Institute for Chemical and Bioengineering, ETH Zurich, 8093 Zurich, Switzerland, and Paul Scherrer Institute, 5232 Villigen, SwitzerlandAndrew D. D’AmicoETH ZurichNadiya DanilinaSchool of Chemical & Biomolecular Engineering, Georgia Institute of Technology, 311 Ferst Drive NW, Atlanta, Georgia 30332-0100, United States, Department of Chemistry and Catalysis Research Center, Technische Universität München, Lichtenbergstraβe 4, 85747 Garching, Germany, Institute for Chemical and Bioengineering, ETH Zurich, 8093 Zurich, Switzerland, and Paul Scherrer Institute, 5232 Villigen, SwitzerlandJeroen A. van BokhovenSchool of Chemical & Biomolecular Engineering, Georgia Institute of Technology, 311 Ferst Drive NW, Atlanta, Georgia 30332-0100, United States, Department of Chemistry and Catalysis Research Center, Technische Universität München, Lichtenbergstraβe 4, 85747 Garching, Germany, Institute for Chemical and Bioengineering, ETH Zurich, 8093 Zurich, Switzerland, and Paul Scherrer Institute, 5232 Villigen, SwitzerlandJohannes A. LercherSchool of Chemical & Biomolecular Engineering, Georgia Institute of Technology, 311 Ferst Drive NW, Atlanta, Georgia 30332-0100, United States, Department of Chemistry and Catalysis Research Center, Technische Universität München, Lichtenbergstraβe 4, 85747 Garching, Germany, Institute for Chemical and Bioengineering, ETH Zurich, 8093 Zurich, Switzerland, and Paul Scherrer Institute, 5232 Villigen, SwitzerlandChristopher W. JonesSchool of Chemical & Biomolecular Engineering, Georgia Institute of Technology, 311 Ferst Drive NW, Atlanta, Georgia 30332-0100, United States, Department of Chemistry and Catalysis Research Center, Technische Universität München, Lichtenbergstraβe 4, 85747 Garching, Germany, Institute for Chemical and Bioengineering, ETH Zurich, 8093 Zurich, Switzerland, and Paul Scherrer Institute, 5232 Villigen, SwitzerlandCarsten SieversSchool of Chemical & Biomolecular Engineering, Georgia Institute of Technology, 311 Ferst Drive NW, Atlanta, Georgia 30332-0100, United States, Department of Chemistry and Catalysis Research Center, Technische Universität München, Lichtenbergstraβe 4, 85747 Garching, Germany, Institute for Chemical and Bioengineering, ETH Zurich, 8093 Zurich, Switzerland, and Paul Scherrer Institute, 5232 Villigen, Switzerland

2010en

ABI

Аннотация

Zeolites Y and ZSM-5 with varying Si/Al ratios are treated in liquid water at 150 and 200 °C under autogenic pressure to assess their hydrothermal stability. The changes in the structure are characterized by atomic absorption spectroscopy, X-ray diffraction, scanning electron microscopy, argon physisorption, 27Al and 29Si MAS NMR spectroscopy, temperature-programmed desorption of ammonia, and pyridine adsorption followed by IR spectroscopy. During treatment in hot water, zeolite Y with a Si/Al ratio of 14 or higher is transformed into an amorphous material, and the rate of this degradation increases with increasing Si/Al ratio. In contrast, ZSM-5 is not modified under the same conditions. The main degradation mechanism is suggested to be hydrolysis of the siloxane bonds (Si−O−Si) as opposed to dealumination, which dominates under steaming conditions. In the resulting amorphous phase, Al remains tetrahedrally coordinated, but the micropore volume and concentration of accessible acid sites is reduced dramatically. The results demonstrate that potential structural changes of zeolites have to be considered when these materials are used as catalysts for aqueous phase conversion of biomass.

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Идентификаторы

DOI: 10.1021/jp104639e

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Цитирований: 2Использованных источников: 0

Показатели — AkademScholar