Sulfonic acid-functionalized mesoporous carbon/silica as efficient catalyst for dehydration of fructose into 5-hydroxymethylfurfural†
Abstract
Mesoporous silica with desired pore structure (the appropriate channel length and pore size) was synthesized through a modified soft template method. Amorphous carbon layers were then introduced in mesoporous silica channels through infiltration of carbon precursor and carbonization processes. Finally, sulfonic acid groups (–SO3H) attached onto the amorphous carbons by sulfonation reaction to form sulfonic acid-functionalized mesoporous carbon/silica which was used as a sulfonic acid catalyst. The morphology, pore structure, surface functional groups, and compositions of the obtained sulfonic acid-functionalized mesoporous carbon/silica were investigated by field-emission scanning electron microscopy (SEM), transmission electron microscopy (TEM), N2 adsorption–desorption isotherm, X-ray photoelectron spectroscopy, thermogravimetric analysis and X-ray diffraction techniques. These materials are active for the catalytic dehydration of fructose into 5-hydroxymethylfurfural. The pore structure of hard template-mesoporous silica, and homogeneous coating of amorphous carbon layers are found to be critical to obtain sulfonic acid-functionalized mesoporous carbon/silica with enhanced catalytic activity. The sulfonic acid-functionalized mesoporous carbon/silica synthesized in the desired way could exhibit a high yield of 5-HMF and good recyclability, making them highly applicable in practical applications.