Synthesis and characterization of colloidal TBA-silicalite-2

Abstract

Colloidal TBA-silicalite-2 (MEL type) was hydrothermally synthesized in the reactant system TBAOH–TEOS–H 2O. The influences of reactant composition, reaction temperature, and crystallization period on particle size of the zeolite were investigated. The colloidal silicalite-2 was characterized by XRD, SEM, TEM, FT-IR, 29Si MAS NMR, 13C CP MAS NMR, thermogravimetric analysis and N 2 adsorption. The as-synthesized colloidal zeolite with a particle size of 100 nm is an agglomerate composed of nano-sized crystals of about 20 nm, displaying unique structural characteristics such as high content of silanol defects in the framework, splitting of the double-ring vibration in FT-IR spectrum and an unusual signal for methyl groups of TBA in 13C CP MAS NMR spectrum.