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Al-containing MCM-41 type materials prepared by different synthesis methods: hydrothermal stability and catalytic properties

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Pertenece a: Sapientia Repositório Institucional Universidade do Algarve  

Descripción: 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.

Autor(es): Lourenço, J. P. -  Fernandes, A. -  Henriques, C. -  Ribeiro, M. F. - 

Id.: 55224423

Idioma: eng  - 

Versión: 1.0

Estado: Final

Palabras claveAlpha -  pinene - 

Tipo de recurso: article  - 

Tipo de Interactividad: Expositivo

Nivel de Interactividad: muy bajo

Audiencia: Estudiante  -  Profesor  -  Autor  - 

Estructura: Atomic

Coste: no

Copyright: sí

: openAccess

Requerimientos técnicos:  Browser: Any - 

Fecha de contribución: 15-oct-2013

Contacto:

Localización:
* 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.


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