Syntheses of high quality KIT-6 and SBA-15 mesoporous silicas using low-cost water glass, through rapid quenching of silicate structure in acidic solution

KIT-6 and SBA-15 ordered mesoporous silicas were obtained under various synthesis conditions using water glass as a low-cost silica source. The products were characterized with X-ray powder diffraction, N₂ adsorption, transmission electron microscopy, and scanning electron microscopy. The result showed that the initial mixing condition was a decisive factor for the structural order and mesoporosity. High-quality KIT-6 and SBA-15, even better than products from tetraethoxysilane, were obtained when the reactants were mixed very rapidly to cause instant quenching of silicate structures in acidic solution containing non-ionic surfactants. This procedure was highly reproducible and suitable for a large-scale synthesis.