Sulfonated mesoporous silica–carbon composites and their use as solid acid catalysts

[EN] The synthesis of highly functionalized porous silica–carbon composites made up of sulfonic groups attached to a carbon layer coating the pores of three types of mesostructured silica (i.e. SBA-15, KIT-6 and mesocellular silica) is presented. The synthesis procedure involves the following steps:...

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Detalhes bibliográficos
Autores: Valle Vigón, Patricia, Sevilla Solís, Marta, Fuertes Arias, Antonio Benito
Tipo de documento: artigo
Estado:Versión aceptada para publicación
Data de publicação:2012
País:España
Recursos:Consejo Superior de Investigaciones Científicas (CSIC)
Repositório:DIGITAL.CSIC. Repositorio Institucional del CSIC
OAI Identifier:oai:digital.csic.es:10261/94145
Acesso em linha:http://hdl.handle.net/10261/94145
Access Level:Acceso aberto
Palavra-chave:Silica
Carbon
Composite
Mesoporous
Sulfonation
Solid acid
Catalyst
Esterification
Descrição
Resumo:[EN] The synthesis of highly functionalized porous silica–carbon composites made up of sulfonic groups attached to a carbon layer coating the pores of three types of mesostructured silica (i.e. SBA-15, KIT-6 and mesocellular silica) is presented. The synthesis procedure involves the following steps: (a) removal of the surfactant, (b) impregnation of the silica pores with a carbon precursor, (c) carbonization and (d) sulfonation. The resulting silica–carbon composites contain ∼30 wt % of carbonaceous matter with a high density of acidic groups attached to the deposited carbon (i.e.single bondSO3H, single bondCOOH and single bondOH). The structural characteristics of the parent silica are retained in the composite materials, which exhibit a high surface area, a large pore volume and a well-ordered porosity made up uniform mesopores. The high density of the sulfonic groups in combination with the mesoporous structure of the composites ensures that a large number of active sites are easily accessible to reactants. These sulfonated silica–carbon composites behave as eco-friendly, active, selective, water tolerant and recyclable solid acids. In this study we demonstrate the usefulness of these composites as solid acid catalysts for the esterification of maleic anhydride, succinic acid and oleic acid with ethanol. These composites exhibit a superior intrinsic catalytic activity to other commercial solid acids such as Amberlyst-15.