Al-containing MCM-41 type materials prepared by different synthesis methods: hydrothermal stability and catalytic properties
Autor(a) principal: | |
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Data de Publicação: | 2006 |
Outros Autores: | , , |
Tipo de documento: | Artigo |
Idioma: | eng |
Título da fonte: | Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) |
Texto Completo: | http://hdl.handle.net/10400.1/1081 |
Resumo: | Al-containing MCM-41 type materials were prepared by three different synthesis methods (aluminum grafting on the calcined MCM-41, pH adjustment during the crystallization period and crystallization in the presence of zeolite seeds). The samples were characterized by powder XRD, nitrogen adsorption, 27Al MAS NMR and FTIR with pyridine as probe molecule. All the samples exhibit a high hydrothermal stability at high temperature just with a minor structural degradation. N2 adsorption data obtained for the sample prepared from a gel containing zeolite seeds suggest a higher structural resistance to the hydrothermal treatment in comparison with the samples prepared by other methods. A different type of pyridine adsorbed, probably interacting simultaneously with a Brönsted and a Lewis acid site, is observed upon pyridine adsorption. This type of adsorption is stronger for the sample prepared in the presence of zeolite seeds and is not observed on Al-grafted MCM-41. 2 The catalytic activity towards the isomerization of α-pinene depends mainly on the number of Brönsted acid sites. The data obtained in this study strongly indicate that for this type of materials, the Lewis acid sites do not influence the selectivity for the isomerization products. |
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Al-containing MCM-41 type materials prepared by different synthesis methods: hydrothermal stability and catalytic propertiesAlpha-pineneMCM-41SynthesisHydrothermal stabilityCatalytic activityAl-containing MCM-41 type materials were prepared by three different synthesis methods (aluminum grafting on the calcined MCM-41, pH adjustment during the crystallization period and crystallization in the presence of zeolite seeds). The samples were characterized by powder XRD, nitrogen adsorption, 27Al MAS NMR and FTIR with pyridine as probe molecule. All the samples exhibit a high hydrothermal stability at high temperature just with a minor structural degradation. N2 adsorption data obtained for the sample prepared from a gel containing zeolite seeds suggest a higher structural resistance to the hydrothermal treatment in comparison with the samples prepared by other methods. A different type of pyridine adsorbed, probably interacting simultaneously with a Brönsted and a Lewis acid site, is observed upon pyridine adsorption. This type of adsorption is stronger for the sample prepared in the presence of zeolite seeds and is not observed on Al-grafted MCM-41. 2 The catalytic activity towards the isomerization of α-pinene depends mainly on the number of Brönsted acid sites. The data obtained in this study strongly indicate that for this type of materials, the Lewis acid sites do not influence the selectivity for the isomerization products.SapientiaLourenço, João P.Fernandes, A.Henriques, C.Ribeiro, M. F.2012-04-26T13:03:54Z20062012-04-25T10:18:26Z2006-01-01T00:00:00Zinfo:eu-repo/semantics/publishedVersioninfo:eu-repo/semantics/articleapplication/pdfhttp://hdl.handle.net/10400.1/1081engLourenço, J. P.; Fernandes, A.; Henriques, C.; Ribeiro, M.F. Al-containing MCM-41 type materials prepared by different synthesis methods: hydrothermal stability and catalytic properties. Microporous and Mesoporous Materials, 94, 56-65, 2006.AUT: JLO01215;info:eu-repo/semantics/openAccessreponame:Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)instname:Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informaçãoinstacron:RCAAP2023-07-24T10:12:02Zoai:sapientia.ualg.pt:10400.1/1081Portal AgregadorONGhttps://www.rcaap.pt/oai/openaireopendoar:71602024-03-19T19:55:18.209172Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) - Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informaçãofalse |
dc.title.none.fl_str_mv |
Al-containing MCM-41 type materials prepared by different synthesis methods: hydrothermal stability and catalytic properties |
title |
Al-containing MCM-41 type materials prepared by different synthesis methods: hydrothermal stability and catalytic properties |
spellingShingle |
Al-containing MCM-41 type materials prepared by different synthesis methods: hydrothermal stability and catalytic properties Lourenço, João P. Alpha-pinene MCM-41 Synthesis Hydrothermal stability Catalytic activity |
title_short |
Al-containing MCM-41 type materials prepared by different synthesis methods: hydrothermal stability and catalytic properties |
title_full |
Al-containing MCM-41 type materials prepared by different synthesis methods: hydrothermal stability and catalytic properties |
title_fullStr |
Al-containing MCM-41 type materials prepared by different synthesis methods: hydrothermal stability and catalytic properties |
title_full_unstemmed |
Al-containing MCM-41 type materials prepared by different synthesis methods: hydrothermal stability and catalytic properties |
title_sort |
Al-containing MCM-41 type materials prepared by different synthesis methods: hydrothermal stability and catalytic properties |
author |
Lourenço, João P. |
author_facet |
Lourenço, João P. Fernandes, A. Henriques, C. Ribeiro, M. F. |
author_role |
author |
author2 |
Fernandes, A. Henriques, C. Ribeiro, M. F. |
author2_role |
author author author |
dc.contributor.none.fl_str_mv |
Sapientia |
dc.contributor.author.fl_str_mv |
Lourenço, João P. Fernandes, A. Henriques, C. Ribeiro, M. F. |
dc.subject.por.fl_str_mv |
Alpha-pinene MCM-41 Synthesis Hydrothermal stability Catalytic activity |
topic |
Alpha-pinene MCM-41 Synthesis Hydrothermal stability Catalytic activity |
description |
Al-containing MCM-41 type materials were prepared by three different synthesis methods (aluminum grafting on the calcined MCM-41, pH adjustment during the crystallization period and crystallization in the presence of zeolite seeds). The samples were characterized by powder XRD, nitrogen adsorption, 27Al MAS NMR and FTIR with pyridine as probe molecule. All the samples exhibit a high hydrothermal stability at high temperature just with a minor structural degradation. N2 adsorption data obtained for the sample prepared from a gel containing zeolite seeds suggest a higher structural resistance to the hydrothermal treatment in comparison with the samples prepared by other methods. A different type of pyridine adsorbed, probably interacting simultaneously with a Brönsted and a Lewis acid site, is observed upon pyridine adsorption. This type of adsorption is stronger for the sample prepared in the presence of zeolite seeds and is not observed on Al-grafted MCM-41. 2 The catalytic activity towards the isomerization of α-pinene depends mainly on the number of Brönsted acid sites. The data obtained in this study strongly indicate that for this type of materials, the Lewis acid sites do not influence the selectivity for the isomerization products. |
publishDate |
2006 |
dc.date.none.fl_str_mv |
2006 2006-01-01T00:00:00Z 2012-04-26T13:03:54Z 2012-04-25T10:18:26Z |
dc.type.status.fl_str_mv |
info:eu-repo/semantics/publishedVersion |
dc.type.driver.fl_str_mv |
info:eu-repo/semantics/article |
format |
article |
status_str |
publishedVersion |
dc.identifier.uri.fl_str_mv |
http://hdl.handle.net/10400.1/1081 |
url |
http://hdl.handle.net/10400.1/1081 |
dc.language.iso.fl_str_mv |
eng |
language |
eng |
dc.relation.none.fl_str_mv |
Lourenço, J. P.; Fernandes, A.; Henriques, C.; Ribeiro, M.F. Al-containing MCM-41 type materials prepared by different synthesis methods: hydrothermal stability and catalytic properties. Microporous and Mesoporous Materials, 94, 56-65, 2006. AUT: JLO01215; |
dc.rights.driver.fl_str_mv |
info:eu-repo/semantics/openAccess |
eu_rights_str_mv |
openAccess |
dc.format.none.fl_str_mv |
application/pdf |
dc.source.none.fl_str_mv |
reponame:Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) instname:Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informação instacron:RCAAP |
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Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informação |
instacron_str |
RCAAP |
institution |
RCAAP |
reponame_str |
Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) |
collection |
Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) |
repository.name.fl_str_mv |
Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) - Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informação |
repository.mail.fl_str_mv |
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1799133154995339264 |