Catalytic performance and deactivation of sulfonated hydrothermal carbon in the esterification of fatty acids: Comparison with sulfonic solids of different nature

Sulfonated hydrothermal carbon is able to catalyze the esterification of palmitic acid with methanol at a higher initial rate per site than other well-known sulfonic solids, including stronger acids such as Nafion-silica. Although the origin of this higher rate per site is not clear, it seems to be...

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Detalles Bibliográficos
Autores: Fraile, José M., García-Bordejé, José Enrique, Pires, Elísabet, Roldán, Laura
Tipo de recurso: artículo
Estado:Versión aceptada para publicación
Fecha de publicación:2015
País:España
Institución:Consejo Superior de Investigaciones Científicas (CSIC)
Repositorio:DIGITAL.CSIC. Repositorio Institucional del CSIC
OAI Identifier:oai:digital.csic.es:10261/154638
Acceso en línea:http://hdl.handle.net/10261/154638
Access Level:acceso abierto
Palabra clave:Sulfonated hydrothermal carbon
Acid catalysts
Esterification
Deactivation
Sulfonic solids
Descripción
Sumario:Sulfonated hydrothermal carbon is able to catalyze the esterification of palmitic acid with methanol at a higher initial rate per site than other well-known sulfonic solids, including stronger acids such as Nafion-silica. Although the origin of this higher rate per site is not clear, it seems to be related to high surface density of acid groups (both carboxylic and sulfonic). At the same time, their close proximity makes possible the mutual activation of the surface groups for esterification with methanol. The formation of sulfonate esters on the surface produces irreversible partial deactivation of the solid for a second reaction. Other solids able to bring sulfonic groups close, such as Dowex, show the same deactivation pattern, but their sites are less active than those in sulfonated hydrothermal carbon. As an additional advantage, this solid displays enhanced stability against the presence of water, which enables improvement of the behavior after recovery by minimization of the esterification of the surface acid sites.