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Cooperativity between Al Sites Promotes Hydrogen Transfer and Carbon–Carbon Bond Formation upon Dimethyl Ether Activation on Alumina

[Image: see text] The methanol-to-olefin (MTO) process allows the conversion of methanol/dimethyl ether into olefins on acidic zeolites via the so-called hydrocarbon pool mechanism. However, the site and mechanism of formation of the first carbon–carbon bond are still a matter of debate. Here, we sh...

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Autores principales: Comas-Vives, Aleix, Valla, Maxence, Copéret, Christophe, Sautet, Philippe
Formato: Online Artículo Texto
Lenguaje:English
Publicado: American Chemical Society 2015
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4827526/
https://www.ncbi.nlm.nih.gov/pubmed/27162986
http://dx.doi.org/10.1021/acscentsci.5b00226
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author Comas-Vives, Aleix
Valla, Maxence
Copéret, Christophe
Sautet, Philippe
author_facet Comas-Vives, Aleix
Valla, Maxence
Copéret, Christophe
Sautet, Philippe
author_sort Comas-Vives, Aleix
collection PubMed
description [Image: see text] The methanol-to-olefin (MTO) process allows the conversion of methanol/dimethyl ether into olefins on acidic zeolites via the so-called hydrocarbon pool mechanism. However, the site and mechanism of formation of the first carbon–carbon bond are still a matter of debate. Here, we show that the Lewis acidic Al sites on the 110 facet of γ-Al(2)O(3) can readily activate dimethyl ether to yield CH(4), alkenes, and surface formate species according to spectroscopic studies combined with a computational approach. The carbon–carbon forming step as well as the formation of methane and surface formate involves a transient oxonium ion intermediate, generated by a hydrogen transfer between surface methoxy species and coordinated methanol on adjacent Al sites. These results indicate that extra framework Al centers in acidic zeolites, which are associated with alumina, can play a key role in the formation of the first carbon–carbon bond, the initiation step of the industrial MTO process.
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spelling pubmed-48275262016-05-09 Cooperativity between Al Sites Promotes Hydrogen Transfer and Carbon–Carbon Bond Formation upon Dimethyl Ether Activation on Alumina Comas-Vives, Aleix Valla, Maxence Copéret, Christophe Sautet, Philippe ACS Cent Sci [Image: see text] The methanol-to-olefin (MTO) process allows the conversion of methanol/dimethyl ether into olefins on acidic zeolites via the so-called hydrocarbon pool mechanism. However, the site and mechanism of formation of the first carbon–carbon bond are still a matter of debate. Here, we show that the Lewis acidic Al sites on the 110 facet of γ-Al(2)O(3) can readily activate dimethyl ether to yield CH(4), alkenes, and surface formate species according to spectroscopic studies combined with a computational approach. The carbon–carbon forming step as well as the formation of methane and surface formate involves a transient oxonium ion intermediate, generated by a hydrogen transfer between surface methoxy species and coordinated methanol on adjacent Al sites. These results indicate that extra framework Al centers in acidic zeolites, which are associated with alumina, can play a key role in the formation of the first carbon–carbon bond, the initiation step of the industrial MTO process. American Chemical Society 2015-08-05 2015-09-23 /pmc/articles/PMC4827526/ /pubmed/27162986 http://dx.doi.org/10.1021/acscentsci.5b00226 Text en Copyright © 2015 American Chemical Society This is an open access article published under an ACS AuthorChoice License (http://pubs.acs.org/page/policy/authorchoice_termsofuse.html) , which permits copying and redistribution of the article or any adaptations for non-commercial purposes.
spellingShingle Comas-Vives, Aleix
Valla, Maxence
Copéret, Christophe
Sautet, Philippe
Cooperativity between Al Sites Promotes Hydrogen Transfer and Carbon–Carbon Bond Formation upon Dimethyl Ether Activation on Alumina
title Cooperativity between Al Sites Promotes Hydrogen Transfer and Carbon–Carbon Bond Formation upon Dimethyl Ether Activation on Alumina
title_full Cooperativity between Al Sites Promotes Hydrogen Transfer and Carbon–Carbon Bond Formation upon Dimethyl Ether Activation on Alumina
title_fullStr Cooperativity between Al Sites Promotes Hydrogen Transfer and Carbon–Carbon Bond Formation upon Dimethyl Ether Activation on Alumina
title_full_unstemmed Cooperativity between Al Sites Promotes Hydrogen Transfer and Carbon–Carbon Bond Formation upon Dimethyl Ether Activation on Alumina
title_short Cooperativity between Al Sites Promotes Hydrogen Transfer and Carbon–Carbon Bond Formation upon Dimethyl Ether Activation on Alumina
title_sort cooperativity between al sites promotes hydrogen transfer and carbon–carbon bond formation upon dimethyl ether activation on alumina
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4827526/
https://www.ncbi.nlm.nih.gov/pubmed/27162986
http://dx.doi.org/10.1021/acscentsci.5b00226
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