Amorphous Carbon Bearing Sulfonic Acid Groups in Mesoporous Silica as a Selective Catalyst

Abstract

Sulfonic acid group (SO 3 H)-bearing amorphous carbon/mesoporous silica composites were studied for use as solid acid catalysts. Sugar-derived amorphous carbon with SO 3 H cannot catalyze hydrophobic acid-catalyzed reactions, such as the dimerization of α-methylstyrene, because of the small surface area. However, SO 3 H-bearing sugar-derived amorphous carbon supported on mesoporous silica exhibits remarkable catalytic performance for the dimerization of α-methylstyrene. Under optimal conditions, the selectivity of the composite catalysts for unsaturated dimers exceeds 98%. Structural and reaction analyses revealed that SO 3 H-bearing carbon particles with large surface areas are formed in the mesopores and prevent intramolecular Friedel−Crafts alkylation, resulting in high catalytic activity.