Dehydrocyclization of n-heptane over a PtBa/Kl catalyst: Reaction mechanism

Autores
Arcoya, Adolfo; Seoane, Xosé L.; Grau, Javier Mario
Año de publicación
2005
Idioma
inglés
Tipo de recurso
artículo
Estado
versión publicada
Descripción
The dehydrocyclization of n-heptane to toluene over a 1 wt.% PtBa/KL catalyst was studied in a fixed bed tubular reactor, at 723 K, 100 kPa and space-time in the range of 1.8-117.0 g h mol-1. The catalyst was prepared by incipient wetness impregnation of a KL zeolite, previously alkalized with BaO, using an aqueous solution of tetraammineplatinum(II) hydroxide as platinum precursor. The solid was successively calcined in an oxygen stream and reduced in flowing hydrogen, at 773 K. Reaction is highly selective towards toluene (>60%) at conversion levels even close to 100%, with benzene, heptenes, methylcyclohexane and ethylcyclopentane as major byproducts. From the product distribution and the dehydrocyclization results of the reaction products performed in separate experiments, a macroscopic mechanism is proposed. Essentially, n-heptane is adsorbed and transformed on the catalyst surface through an alkene-like intermediate (σC7=), following five possible parallel interconnected paths, involving hydrogenolysis, isomerization, dehydrogenation and cyclization reactions. Formation of toluene as a primary product is explained by a "rake scheme" in which the σC7= intermediate is successively transformed, following two possible routes: (a) C1-C6 ring closure and subsequent further dehydrogenation; (b) successive dehydrogenation to heptatriene and then cyclization to toluene. These transformations occur in the adsorbed phase and on the same active site, in such a way that only a small fraction of the total adsorbed intermediates formed appear in the gas phase. The rest are not desorbed due to their high reactivity.
Fil: Arcoya, Adolfo. Consejo Superior de Investigaciones Científicas. Instituto de Catálisis y Petroleoquímica; España
Fil: Seoane, Xosé L.. Consejo Superior de Investigaciones Científicas. Instituto de Catálisis y Petroleoquímica; España
Fil: Grau, Javier Mario. Consejo Superior de Investigaciones Científicas. Instituto de Catálisis y Petroleoquímica; España. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Investigaciones en Catálisis y Petroquímica "Ing. José Miguel Parera". Universidad Nacional del Litoral. Instituto de Investigaciones en Catálisis y Petroquímica "Ing. José Miguel Parera"; Argentina
Materia
Ethylcyclopentane
Methylcyclohexane
N-Heptane Dehydrocyclization Mechanism
Pt/Kl Catalysts
Toluene
Nivel de accesibilidad
acceso abierto
Condiciones de uso
https://creativecommons.org/licenses/by-nc-nd/2.5/ar/
Repositorio
CONICET Digital (CONICET)
Institución
Consejo Nacional de Investigaciones Científicas y Técnicas
OAI Identificador
oai:ri.conicet.gov.ar:11336/55357
Acceder
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oai_identifier_str oai:ri.conicet.gov.ar:11336/55357
network_acronym_str CONICETDig
repository_id_str 3498
network_name_str CONICET Digital (CONICET)
spelling Dehydrocyclization of n-heptane over a PtBa/Kl catalyst: Reaction mechanismArcoya, AdolfoSeoane, Xosé L.Grau, Javier MarioEthylcyclopentaneMethylcyclohexaneN-Heptane Dehydrocyclization MechanismPt/Kl CatalystsToluenehttps://purl.org/becyt/ford/2.4https://purl.org/becyt/ford/2The dehydrocyclization of n-heptane to toluene over a 1 wt.% PtBa/KL catalyst was studied in a fixed bed tubular reactor, at 723 K, 100 kPa and space-time in the range of 1.8-117.0 g h mol-1. The catalyst was prepared by incipient wetness impregnation of a KL zeolite, previously alkalized with BaO, using an aqueous solution of tetraammineplatinum(II) hydroxide as platinum precursor. The solid was successively calcined in an oxygen stream and reduced in flowing hydrogen, at 773 K. Reaction is highly selective towards toluene (>60%) at conversion levels even close to 100%, with benzene, heptenes, methylcyclohexane and ethylcyclopentane as major byproducts. From the product distribution and the dehydrocyclization results of the reaction products performed in separate experiments, a macroscopic mechanism is proposed. Essentially, n-heptane is adsorbed and transformed on the catalyst surface through an alkene-like intermediate (σC7=), following five possible parallel interconnected paths, involving hydrogenolysis, isomerization, dehydrogenation and cyclization reactions. Formation of toluene as a primary product is explained by a "rake scheme" in which the σC7= intermediate is successively transformed, following two possible routes: (a) C1-C6 ring closure and subsequent further dehydrogenation; (b) successive dehydrogenation to heptatriene and then cyclization to toluene. These transformations occur in the adsorbed phase and on the same active site, in such a way that only a small fraction of the total adsorbed intermediates formed appear in the gas phase. The rest are not desorbed due to their high reactivity.Fil: Arcoya, Adolfo. Consejo Superior de Investigaciones Científicas. Instituto de Catálisis y Petroleoquímica; EspañaFil: Seoane, Xosé L.. Consejo Superior de Investigaciones Científicas. Instituto de Catálisis y Petroleoquímica; EspañaFil: Grau, Javier Mario. Consejo Superior de Investigaciones Científicas. Instituto de Catálisis y Petroleoquímica; España. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Investigaciones en Catálisis y Petroquímica "Ing. José Miguel Parera". Universidad Nacional del Litoral. Instituto de Investigaciones en Catálisis y Petroquímica "Ing. José Miguel Parera"; ArgentinaElsevier Science2005-04info:eu-repo/semantics/articleinfo:eu-repo/semantics/publishedVersionhttp://purl.org/coar/resource_type/c_6501info:ar-repo/semantics/articuloapplication/pdfapplication/pdfhttp://hdl.handle.net/11336/55357Arcoya, Adolfo; Seoane, Xosé L.; Grau, Javier Mario; Dehydrocyclization of n-heptane over a PtBa/Kl catalyst: Reaction mechanism; Elsevier Science; Applied Catalysis A: General; 284; 1-2; 4-2005; 85-950926-860XCONICET DigitalCONICETenginfo:eu-repo/semantics/altIdentifier/doi/10.1016/j.apcata.2005.01.024info:eu-repo/semantics/altIdentifier/url/https://www.sciencedirect.com/science/article/pii/S0926860X0500030Xinfo:eu-repo/semantics/openAccesshttps://creativecommons.org/licenses/by-nc-nd/2.5/ar/reponame:CONICET Digital (CONICET)instname:Consejo Nacional de Investigaciones Científicas y Técnicas2025-10-22T11:03:58Zoai:ri.conicet.gov.ar:11336/55357instacron:CONICETInstitucionalhttp://ri.conicet.gov.ar/Organismo científico-tecnológicoNo correspondehttp://ri.conicet.gov.ar/oai/requestdasensio@conicet.gov.ar; lcarlino@conicet.gov.arArgentinaNo correspondeNo correspondeNo correspondeopendoar:34982025-10-22 11:03:58.929CONICET Digital (CONICET) - Consejo Nacional de Investigaciones Científicas y Técnicasfalse
dc.title.none.fl_str_mv Dehydrocyclization of n-heptane over a PtBa/Kl catalyst: Reaction mechanism
title Dehydrocyclization of n-heptane over a PtBa/Kl catalyst: Reaction mechanism
spellingShingle Dehydrocyclization of n-heptane over a PtBa/Kl catalyst: Reaction mechanism
Arcoya, Adolfo
Ethylcyclopentane
Methylcyclohexane
N-Heptane Dehydrocyclization Mechanism
Pt/Kl Catalysts
Toluene
title_short Dehydrocyclization of n-heptane over a PtBa/Kl catalyst: Reaction mechanism
title_full Dehydrocyclization of n-heptane over a PtBa/Kl catalyst: Reaction mechanism
title_fullStr Dehydrocyclization of n-heptane over a PtBa/Kl catalyst: Reaction mechanism
title_full_unstemmed Dehydrocyclization of n-heptane over a PtBa/Kl catalyst: Reaction mechanism
title_sort Dehydrocyclization of n-heptane over a PtBa/Kl catalyst: Reaction mechanism
dc.creator.none.fl_str_mv Arcoya, Adolfo
Seoane, Xosé L.
Grau, Javier Mario
author Arcoya, Adolfo
author_facet Arcoya, Adolfo
Seoane, Xosé L.
Grau, Javier Mario
author_role author
author2 Seoane, Xosé L.
Grau, Javier Mario
author2_role author
author
dc.subject.none.fl_str_mv Ethylcyclopentane
Methylcyclohexane
N-Heptane Dehydrocyclization Mechanism
Pt/Kl Catalysts
Toluene
topic Ethylcyclopentane
Methylcyclohexane
N-Heptane Dehydrocyclization Mechanism
Pt/Kl Catalysts
Toluene
purl_subject.fl_str_mv https://purl.org/becyt/ford/2.4
https://purl.org/becyt/ford/2
dc.description.none.fl_txt_mv The dehydrocyclization of n-heptane to toluene over a 1 wt.% PtBa/KL catalyst was studied in a fixed bed tubular reactor, at 723 K, 100 kPa and space-time in the range of 1.8-117.0 g h mol-1. The catalyst was prepared by incipient wetness impregnation of a KL zeolite, previously alkalized with BaO, using an aqueous solution of tetraammineplatinum(II) hydroxide as platinum precursor. The solid was successively calcined in an oxygen stream and reduced in flowing hydrogen, at 773 K. Reaction is highly selective towards toluene (>60%) at conversion levels even close to 100%, with benzene, heptenes, methylcyclohexane and ethylcyclopentane as major byproducts. From the product distribution and the dehydrocyclization results of the reaction products performed in separate experiments, a macroscopic mechanism is proposed. Essentially, n-heptane is adsorbed and transformed on the catalyst surface through an alkene-like intermediate (σC7=), following five possible parallel interconnected paths, involving hydrogenolysis, isomerization, dehydrogenation and cyclization reactions. Formation of toluene as a primary product is explained by a "rake scheme" in which the σC7= intermediate is successively transformed, following two possible routes: (a) C1-C6 ring closure and subsequent further dehydrogenation; (b) successive dehydrogenation to heptatriene and then cyclization to toluene. These transformations occur in the adsorbed phase and on the same active site, in such a way that only a small fraction of the total adsorbed intermediates formed appear in the gas phase. The rest are not desorbed due to their high reactivity.
Fil: Arcoya, Adolfo. Consejo Superior de Investigaciones Científicas. Instituto de Catálisis y Petroleoquímica; España
Fil: Seoane, Xosé L.. Consejo Superior de Investigaciones Científicas. Instituto de Catálisis y Petroleoquímica; España
Fil: Grau, Javier Mario. Consejo Superior de Investigaciones Científicas. Instituto de Catálisis y Petroleoquímica; España. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Investigaciones en Catálisis y Petroquímica "Ing. José Miguel Parera". Universidad Nacional del Litoral. Instituto de Investigaciones en Catálisis y Petroquímica "Ing. José Miguel Parera"; Argentina
description The dehydrocyclization of n-heptane to toluene over a 1 wt.% PtBa/KL catalyst was studied in a fixed bed tubular reactor, at 723 K, 100 kPa and space-time in the range of 1.8-117.0 g h mol-1. The catalyst was prepared by incipient wetness impregnation of a KL zeolite, previously alkalized with BaO, using an aqueous solution of tetraammineplatinum(II) hydroxide as platinum precursor. The solid was successively calcined in an oxygen stream and reduced in flowing hydrogen, at 773 K. Reaction is highly selective towards toluene (>60%) at conversion levels even close to 100%, with benzene, heptenes, methylcyclohexane and ethylcyclopentane as major byproducts. From the product distribution and the dehydrocyclization results of the reaction products performed in separate experiments, a macroscopic mechanism is proposed. Essentially, n-heptane is adsorbed and transformed on the catalyst surface through an alkene-like intermediate (σC7=), following five possible parallel interconnected paths, involving hydrogenolysis, isomerization, dehydrogenation and cyclization reactions. Formation of toluene as a primary product is explained by a "rake scheme" in which the σC7= intermediate is successively transformed, following two possible routes: (a) C1-C6 ring closure and subsequent further dehydrogenation; (b) successive dehydrogenation to heptatriene and then cyclization to toluene. These transformations occur in the adsorbed phase and on the same active site, in such a way that only a small fraction of the total adsorbed intermediates formed appear in the gas phase. The rest are not desorbed due to their high reactivity.
publishDate 2005
dc.date.none.fl_str_mv 2005-04
dc.type.none.fl_str_mv info:eu-repo/semantics/article
info:eu-repo/semantics/publishedVersion
http://purl.org/coar/resource_type/c_6501
info:ar-repo/semantics/articulo
format article
status_str publishedVersion
dc.identifier.none.fl_str_mv http://hdl.handle.net/11336/55357
Arcoya, Adolfo; Seoane, Xosé L.; Grau, Javier Mario; Dehydrocyclization of n-heptane over a PtBa/Kl catalyst: Reaction mechanism; Elsevier Science; Applied Catalysis A: General; 284; 1-2; 4-2005; 85-95
0926-860X
CONICET Digital
CONICET
url http://hdl.handle.net/11336/55357
identifier_str_mv Arcoya, Adolfo; Seoane, Xosé L.; Grau, Javier Mario; Dehydrocyclization of n-heptane over a PtBa/Kl catalyst: Reaction mechanism; Elsevier Science; Applied Catalysis A: General; 284; 1-2; 4-2005; 85-95
0926-860X
CONICET Digital
CONICET
dc.language.none.fl_str_mv eng
language eng
dc.relation.none.fl_str_mv info:eu-repo/semantics/altIdentifier/doi/10.1016/j.apcata.2005.01.024
info:eu-repo/semantics/altIdentifier/url/https://www.sciencedirect.com/science/article/pii/S0926860X0500030X
dc.rights.none.fl_str_mv info:eu-repo/semantics/openAccess
https://creativecommons.org/licenses/by-nc-nd/2.5/ar/
eu_rights_str_mv openAccess
rights_invalid_str_mv https://creativecommons.org/licenses/by-nc-nd/2.5/ar/
dc.format.none.fl_str_mv application/pdf
application/pdf
dc.publisher.none.fl_str_mv Elsevier Science
publisher.none.fl_str_mv Elsevier Science
dc.source.none.fl_str_mv reponame:CONICET Digital (CONICET)
instname:Consejo Nacional de Investigaciones Científicas y Técnicas
reponame_str CONICET Digital (CONICET)
collection CONICET Digital (CONICET)
instname_str Consejo Nacional de Investigaciones Científicas y Técnicas
repository.name.fl_str_mv CONICET Digital (CONICET) - Consejo Nacional de Investigaciones Científicas y Técnicas
repository.mail.fl_str_mv dasensio@conicet.gov.ar; lcarlino@conicet.gov.ar
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score 12.982451

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