Finding the active species: The conversion of methanol to aromatics over Zn-ZSM-5/alumina shaped catalysts
| Autor: | Stian Svelle, Uffe Vie Mentzel, Elisa Borfecchia, Silvia Bordiga, Finn Joensen, Pablo Beato, Tomás Cordero-Lanzac, Kirill A. Lomachenko, Unni Olsbye, Irene Pinilla-Herrero |
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| Rok vydání: | 2021 |
| Předmět: |
XAS
Industrial catalysts Inorganic chemistry 010402 general chemistry 01 natural sciences Catalysis law.invention chemistry.chemical_compound law Calcination Physical and Theoretical Chemistry Zeolite Binder Ion exchange Extrudate 010405 organic chemistry Chemistry X-ray absorption spectroscopy 0104 chemical sciences Methanol to gasoline Yield (chemistry) Methanol ZSM-5 |
| Zdroj: | Journal of Catalysis. 394:416-428 |
| ISSN: | 0021-9517 |
| Popis: | The Zn-loaded zeolite ZSM-5 is an active and promising catalyst for the conversion of methanol to aromatics with high yield. In this work, we have investigated the catalytic performance of shaped Zn-ZSM-5/alumina catalysts in this reaction at industrially relevant pressures. This has been combined with extensive characterization to identify the active Zn species. It is clear that the introduction of Zn leads to an improved catalyst lifetime when the reaction is carried out at elevated pressure. A clear shift from reaction pathways leading to alkane formation to pathways leading to molecular hydrogen formation during the production of aromatics is observed. For industrial catalysts, Zn incorporation is conveniently carried out by impregnation after shaping. A significant migration of Zn into the zeolite ion exchange positions is observed upon calcination of impregnated catalysts, and it is these species that are active for the reaction. At high Zn loadings, ZnAl2O4 species observable by X-ray absorption spectroscopy, but not detectable by diffraction, are formed in the alumina binder. |
| Databáze: | OpenAIRE |
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