Synthesis, characterization and catalytic activity of acid–base bifunctional materials through protection of amino groups

Abstract Acid–base bifunctional mesoporous material SO 3 H-SBA-15-NH 2 was successfully synthesized under low acidic medium through protection of amino groups. X-ray diffraction (XRD), N 2 adsorption–desorption, transmission electron micrographs (TEM), back titration, 13 C magic-angle spinning (MAS) NMR and 29 Si 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 SO 3 H-SBA-15 and SBA-15-NH 2 , the bifunctional sample of SO 3 H-SBA-15-NH 2 containing amine and sulfonic acid groups exhibited excellent acid–basic properties, which make it possess high activity for the aldol condensation.