Microstructural Characterization of Silicalite Crystals Obtained by Sol-Gel Hydrothermal Method

Silicalite films were prepared on three different alumina porous supports by hydrothermal sol-gel synthesis at 160-180 C, using sodium silicate as the silica source and tetrapropylammonium as the templating agent. Studies of the formation of crystals prepared at the same time were used to optimise the growth and structure of the silicalite membranes. Enhanced crystallinity and smaller crystal size was obtained at 180 C. The use of titania as a sintering aid in the alumina support enhanced the homogeneity of the zeolite crystal shape and size. It was concluded that silicalite crystal formation was dependent upon the hydrothermal synthesis conditions, and also the structure of the support. 9 refs.