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Abstract: Acid–base bifunctional mesoporous material SO3H-SBA-15-NH2 was successfully synthesized under low acidic medium through protection of amino groups. X-ray diffraction (XRD), N2 adsorption–desorption, transmission electron micrographs (TEM), back titration, 13C magic-angle spinning (MAS) NMR and 29Si magic-angle spinning (MAS) NMR were employed to characterize the synthesized materials. The obtained bifunctional material was tested for aldol condensation reaction between acetone and 4-nitrobenzaldehyde. Compared with monofunctional catalysts of SO3H-SBA-15 and SBA-15-NH2, the bifunctional sample of SO3H-SBA-15-NH2 containing amine and sulfonic acid groups exhibited excellent acid–basic properties, which make it possess high activity for the aldol condensation. [Copyright &y& Elsevier]

Abstract: Two acid–base bifunctional mesoporous materials Benzyl-APS-S-SBA-15 and Anthracyl-APS-S-SBA-15 (APS: (3-trimethoxysilanyl-propyl)-amine) were successfully synthesized by a direct synthesis method. The influence of steric hindrance upon prevention of interaction between acid and base was investigated by using two different secondary amines, benzyl-(3-trimethoxysilanyl-propyl)-amine and anthracyl methyl-(3-trimethoxysilanyl-propyl)-amine. X-ray diffraction (XRD), N2 adsorption, thermogravimetric analysis (TGA), scanning electron micrographs (SEM), transmission electron micrographs (TEM), elemental analysis, back titration, and 29Si magic-anglespinning (MAS) NMR were employed to characterize the synthesized mesoporous bifunctional materials. The experimental results indicate that the guests can be well dispersed in the channel of SBA-15, and the obtained materials exhibit excellent acid–basic properties, which make it possess high activity for the aldol condensation of acetone with 4-nitrobenzaldehyde. [Copyright &y& Elsevier]