Development of highly active SO3H-modified hybrid mesoporous catalyst

Ethenylene groups on the framework of hybrid mesoporous ethenylene-silica (HME) were successfully modified by a two-step chemical modification (Diels–Alder reaction, sulfonation) to obtain hybrid mesoporous solid acid catalyst. The pendant phenylene groups were first introduced at the ethenylene sites on the surface by the Diels–Alder reaction with benzocyclobutene. The introduced phenylene groups were then sulfonated by simple treatment with concentrated H2SO4. The successful formation of phenylene–sulfonic acid groups at the ethylene sites was confirmed by 13C and 29Si nuclear magnetic resonance (NMR) analysis. X-ray diffraction (XRD) measurements and N2 adsorption analysis revealed the preservation of the original mesoscopic ordering and mesoporosity after the modification. The resulting material exhibited high activity for various acid-catalyzed reactions and can be used repeatedly without deactivation.