Methanol to hydrocarbons over large cavity zeolites: Toward a unified description of catalyst deactivation and the reaction mechanism
| Autor: | Sandrine Benard, Sema Akyalçın, Unni Olsbye, Morten Bjørgen, Stein Kolboe, Stian Svelle |
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| Přispěvatelé: | Anadolu Üniversitesi, Mühendislik Fakültesi, Kimya Mühendisliği Bölümü, Akyalçın, Sema |
| Jazyk: | angličtina |
| Rok vydání: | 2010 |
| Předmět: |
chemistry.chemical_classification
Reaction mechanism Reaction intermediate Heterogeneous catalysis H-Mcm-22 Reaction Mechanism Catalysis Mordenite chemistry.chemical_compound Hydrocarbon chemistry Mtg H-Beta Organic chemistry H-Mordenite Methanol Physical and Theoretical Chemistry Mto Zeolite Mth Isotopic Labeling |
| Popis: | WOS: 000283409900017 The reaction mechanism for the conversion of methanol to hydrocarbons over three large cavity zeolites, H-beta, H-MCM-22, and H-mordenite, has been investigated. (13)C methanol was co-reacted with (12)C benzene to study the buildup and further reactions of the intermediates formed. Co-reaction was required, as these aromatic intermediates will not be formed from pure methanol at temperatures low enough to actually monitor these events. The reactions were followed by dissolving quenched catalysts in HF followed by extraction of the organic compounds and analysis by GC-MS. The same hydrocarbon compounds are formed inside the pores of three zeolites, and it is the most substituted methylbenzenes that function as reaction intermediates in the hydrocarbon pool mechanism for the conversion of methanol. The heptamethylbenzenium cation was for the first time detected and shown to serve as a key reaction intermediate in zeolite catalysts other than H-beta. The formation of bicyclic coke precursors was also investigated, and progress has been made toward a more complete description of the reactions leading to catalyst deactivation. Quantum chemical calculations have shed light on the processes leading to coke precursors. The profound similarities between H-beta, H-mordenite, and H-MCM-22 shown herein constitute a significant step toward a unified understanding of the MTH reaction over acidic zeolites Norwegian Research Council [174893] This publication is part of the inGAP Center of Research Based Innovation, which receives financial support from the Norwegian Research Council under Contract No. 174893. Thanks are also due to the Research Council of Norway for Grant of computer time through the NOTUR Project (Account NN4683K). |
| Databáze: | OpenAIRE |
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