Direct synthesis of highly ordered amine-functionalized mesoporous ethane-silicas

Highly ordered amine-functionalized mesoporous ethane-silicas have been synthesized with P123 as the template under acidic conditions via a simple direct co-condensation method. Addition of inorganic salt KCl during the synthesis can reduce the interference effect of the amine moiety on the co-assembly process and hence increase the structural regularity. Highly ordered mesoporous hybrid materials with different amine contents (up to 40 mol%) were successfully synthesized via the simple direct co-condensation synthesis with the aid of KCl. The hybrid materials exhibit BET surface area of 440–900 m2/g and total pore volume of 0.36–0.99 cm3/g, depending on the amine contents. FT-IR, NMR, TG and elemental analysis results confirm the incorporation of both the bridging ethylene group and the pendant aminopropyl group in the materials. XPS analyses show that most of the protonated amine groups can be converted to free amine groups by base treatment. Moreover, the highly ordered structure was retained after the base treatment. The hybrid materials show high activity in the nitroaldol reaction of benzaldehyde with nitromethane (conversion >99%, selectivity >98%) and can be recycled.