STUDY ON PREPARATION AND PROPERTIES OF NANOPOROUS SILICA/ALUMINA PILLARED MONTMORILLONITE COMPOSITES

The nanoporous silica/alumina pillared montmorillonite composites were synthesized by direct hydrolysis of inorganic aluminum and silicon precursor in the gallery of layered hosts through an intragallery-templated method. Powder X-ray diffraction, TG, FT-IR and N₂ adsorption-desorption isotherms were used to characterize the synthetic Si/Al-clay composite, which was here designated SA-PMH. The results reveal that the SA-PMH exhibits basal spacing of 3.45 nm, a large BET specific area of 502.0 m²/g , an average pore size 2.0 nm and a high thermal stability up to 750 ℃. In comparison to the silica-PMH, little change in textural porosity and thermal stability was observed, but the SA-PMH has more surface acidity and medium-strong acid sites, as confirmed by the temperature-programmed desorption of ammonia and acid-catalyzed reactivity of catechol alkylation with tert-butyl alcohol.