Hydrothermal synthesis of beta zeolite from industrial silica sol as silicon source

The traditional silicon sources for beta zeolite synthesis are solid silica gel, carbon-white or tetraethyl orthosilicate (TEOS), which makes the material cost even higher. Herein, beta zeolite synthesis by hydrothermal method with industrial silica sol as silicon source was investigated. The effects of synthesis conditions on product property were investigated in detail, including template content, crystallization temperature, crystallization time and alkalinity of hydrothermal system. The products properties, such as crystallinity, pore structure, morphology and acid properties were thoroughly characterized by XRD, N₂ adsorption–desorption isotherm, SEM, TEM, Py-FTIR and NH₃-TPD. The optimum condition for synthesis of beta zeolite using industrial silica sol as silicon source was finally determined. Compared with commercial beta zeolite, the as-synthesized beta zeolite had higher relative crystallinity, higher total and microporous specific surface area with higher total concentration and B/L ratio of acid sites.