SYNTHESIS AND CATALYSIS OF MESOPOROUS SILICA-HETEROSTRUCTURED MATERIALS BASED ON MONTMORILLONITE

Based on ion-exchange and self-assembly techniques, a novel nanoporous silica-montmorillonite heterostructured material which exhibits a basal spacing of 37.1 angstrom, gallery height 27.5 angstrom, a BET surface area of 661 m(2)/g and average pore size 25 angstrom has been synthesized. According to XRD, FTIR, TEM and TG results, a new type of porous material is thought to be formed by in situ silica intercalation and assembly. Both the clay:DDA:TEOS molar ratio and reaction time have important effects on the d(001) value and the crystallinity of the final materials. The synthetic material is a potentially effective solid acid catalysts for the Friedel-Crafts alkylation of catechol with tert-butyl alcohol to synthesize butyl 4-tert-butylcatechol (4-TBC). The results show that the bronsted acidity favors the conversion of catechol, but the pore structure controls the selectivity. Over synthetic nanoporous material the selectivity of 4-TBC is 21.2% and the conversion of catechol 77.1 % under experimental conditions. All of results indicate that the silica-montmorillonite heterostructure has great potential applications for larger molecule adsorption and acid catalysis.