Influence of the synthesis conditions on the physicochemical properties and acidity of Al-MCM-41 as catalysts for the cyclohexanone oxime rearrangement

Autores
Vaschetto, Eliana Gabriela; Monti, Gustavo Antonio; Herrero, Eduardo Renato; Casuscelli, Sandra Graciela; Eimer, Griselda Alejandra
Año de publicación
2013
Idioma
inglés
Tipo de recurso
artículo
Estado
Versión publicada
Descripción
Al-containing mesoporous catalysts with MCM-41 structure and high surface area have been successfully prepared by direct hydrothermal synthesis. Various characterization techniques including XRD, N2 adsorption, ICP-OES, NMR, FT-IR and adsorption of pyridine coupled to FT-IR spectroscopy were employed. A detailed study about the relationships existing between the different synthesis parameters, the physico-chemical properties, the acid behavior and the catalytic performance is presented in this contribution. We have suggested that the active sites for the Beckmann rearrangement of cyclohexanone oxime are nest silanols (at structural defects) of very weak Brønsted acid character, which is associated with the introduction of Al into the mesoporous framework. In all the cases, employing soft reaction conditions, we have obtained selectivity to caprolactam of 100%. Finally, a Si/Al initial molar ratio of 20, a stirring of synthesis gel for 7 h and a hydrothermal treatment of 6 days seem to be the optimum synthesis conditions to obtain the highest framework Al incorporation, more abundant weak acid sites (silanol nests) and maximum yield for -caprolactam.
Fil: Vaschetto, Eliana Gabriela. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Centro Cientifico Tecnologico Cordoba. Centro de Investigacion y Tecnologia Quimica; Argentina. Universidad Tecnologica Nacional. Facultad Regional Cordoba; Argentina
Fil: Monti, Gustavo Antonio. Universidad Nacional de Córdoba. Facultad de Matemática, Astronomía y Física; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina
Fil: Herrero, Eduardo Renato. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Centro Cientifico Tecnologico Cordoba. Centro de Investigacion y Tecnologia Quimica; Argentina. Universidad Tecnologica Nacional. Facultad Regional Cordoba; Argentina
Fil: Casuscelli, Sandra Graciela. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Centro Cientifico Tecnologico Cordoba. Centro de Investigacion y Tecnologia Quimica; Argentina. Universidad Tecnologica Nacional. Facultad Regional Cordoba; Argentina
Fil: Eimer, Griselda Alejandra. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Centro Cientifico Tecnologico Cordoba. Centro de Investigacion y Tecnologia Quimica; Argentina. Universidad Tecnologica Nacional. Facultad Regional Cordoba; Argentina
Materia
Mesoporous materials
Al-MCM-41
Synthesis time
Gel stirring
Caprolactam
Otras Ingeniería de los Materiales
Ingeniería de los Materiales
INGENIERÍAS Y TECNOLOGÍAS
Nivel de accesibilidad
Acceso restringido
Licencia
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:11336/10995