Surface properties of mesoporous silicate and alumino-silicate modified by reaction with benzoyl chloride

Abstract

The preparation of mesoporous silicate and alumino-silicate by different synthesis methods are reported together with their surface modification. Specific surface area of starting samples ranges between 400 and 1100 m²/g. Benzoyl chloride was used to graft the benzoyl group to the surface. FT-IR spectra of modified samples show a peak centred at 1705 cm⁻¹ assigned to the stretching vibration of carbonyl group of benzoic ester. The ¹³C NMR spectra also clearly show the benzoyl groups attached at the surface. Modified samples show lower specific surface areas and pore volume with respect to the corresponding values for starting materials. The weight ratio between benzoyl and silica was also calculated by thermogravimetrical analysis. Mesoporous materials and their reactivity open new perspectives in the possibility of designing catalysts.