Full Theoretical Cycle for both Ethene and Propene Formation during Methanol-to-Olefin Conversion in H-ZSM-5
The methanol‐to‐olefin (MTO) process, catalyzed by acidic zeolites such as H‐ZSM‐5, provides an increasingly important alternative to the production of light olefins from crude oil. However, the various mechanistic proposals for methanol‐to‐olefin conversion have been strongly disputed for the past...
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| Vydáno v: | ChemCatChem Ročník 3; číslo 1; s. 208 - 212 |
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| Hlavní autoři: | , , , , |
| Médium: | Journal Article |
| Jazyk: | angličtina |
| Vydáno: |
Weinheim
WILEY-VCH Verlag
10.01.2011
WILEY‐VCH Verlag |
| Témata: | |
| ISSN: | 1867-3880, 1867-3899 |
| On-line přístup: | Získat plný text |
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| Shrnutí: | The methanol‐to‐olefin (MTO) process, catalyzed by acidic zeolites such as H‐ZSM‐5, provides an increasingly important alternative to the production of light olefins from crude oil. However, the various mechanistic proposals for methanol‐to‐olefin conversion have been strongly disputed for the past several decades. This work provides theoretical evidence that the experimentally suggested ‘alkene cycle’, part of a co‐catalytic hydrocarbon pool, offers a viable path to the production of both propene and ethene, in stark contrast to the often‐ proposed direct mechanisms. This specific proposal hinges on repeated methylation reactions of alkenes, starting from propene, which occur easily within the zeolite environment. Subsequent cracking steps regenerate the original propene molecule, while also forming new propene and ethene molecules as primary products. Because the host framework stabilizes intermediate carbenium ions, isomerization and deprotonation reactions are extremely fast. Combined with earlier joint experimental and theoretical work on polymethylbenzenes as active hydrocarbon pool species, it is clear that, in zeolite H‐ZSM‐5, multiple parallel and interlinked routes operate on a competitive basis.
For methanol‐to‐olefin conversion in H‐ZSM‐5, theoretical simulations provide evidence that the ‘alkene cycle’ offers a viable path to the production of both propene and ethene, in contrast to the failing direct mechanisms. Combined with earlier work on polymethylbenzenes as active hydrocarbon pool molecules, it is clear that, in H‐ZSM‐5, multiple parallel and interlinked routes operate on a competitive basis. |
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| Bibliografie: | ark:/67375/WNG-QV36181T-9 BELSPO European Research Council - No. FP7(2007-2013); No. 240483 istex:DB0DECEC99ED086F8A5132449D56F996E36D2946 ArticleID:CCTC201000286 Fund for Scientific Research Flanders Research Board of Ghent University |
| ISSN: | 1867-3880 1867-3899 |
| DOI: | 10.1002/cctc.201000286 |