Acidity effect on benzene methylation kinetics over substituted H-MeAlPO-5 catalysts
| Autor: | Veronique Van Speybroeck, Magnus Mortén, Evgeniy Redekop, Unni Olsbye, Tomás Cordero-Lanzac, Pieter Cnudde, Stian Svelle |
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| Rok vydání: | 2021 |
| Předmět: |
REACTION-MECHANISM
TO-HYDROCARBONS REACTION Technology and Engineering INITIO MOLECULAR-DYNAMICS Kinetics DIMETHYL ETHER Substituent SCALING RELATIONS Medicinal chemistry Catalysis Propene Experimental chemistry.chemical_compound Physical and Theoretical Chemistry Benzene chemistry.chemical_classification AlPO-5 Computational HZSM-5 ZEOLITE Reaction step TOTAL-ENERGY CALCULATIONS Methylation REACTION PATHWAYS GENERALIZED GRADIENT APPROXIMATION MeAlPO-5 Acid strength CO-REACTION MTG chemistry MTO MTH |
| Zdroj: | JOURNAL OF CATALYSIS |
| ISSN: | 0021-9517 1090-2694 |
| Popis: | Methylation of aromatic compounds is a key reaction step in various industrial processes such as the aromatic cycle of methanol-to-hydrocarbons chemistry. The study of isolated methylation reactions and of the influence of catalyst acidity on their kinetics is a challenging task. Herein, we have studied unidirectional metal-substituted H-MeAlPO-5 materials to evaluate the effect of acid strength on the kinetics of benzene methylation with DME. First-principle simulations showed a direct correlation between the methylation barrier and acid site strength, which depends on the metal substituent. Three H-MeAlPO5 catalysts with high (Me = Mg), moderate (Me = Si) and low acidity (Me = Zr) were experimentally tested, confirming a linear relationship between the methylation activation energy and acid strength. The effects of temperature and reactant partial pressure were evaluated, showing significant differences in the byproduct distribution between H-MgAlPO-5 and H-SAPO-5. Comparison with propene methylation suggested that the Mg substituted catalyst is also the most active for the selective methylation of alkenes. (c) 2021 The Author(s). Published by Elsevier Inc. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/). |
| Databáze: | OpenAIRE |
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