Morphology control of self-stacked silicalite-1 crystals using microwave-assisted solvothermal synthesis

Morphology control of silicalite-1 (Si-MFI) crystals was achieved by employing microwave-assisted solvothermal synthesis in the reaction system TEOS-TPAOH-alcohol using dipolar alcohols as a co-solvent. The influences of various experimental parameters, such as dielectric parameters of the alcohols, aging time, and the amount of the alcohols in the reaction mixture on the morphology of the resulting Si-MFI crystals were investigated. Our studies show that self-stacked Si-MFI crystals could be prepared by using alcohols with low dielectric constants as a co-solvent with short aging time and high concentration in the reaction mixture under microwave radiation. The resulting products were further characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), and ²⁹Si MAS NMR analyses.