Synthesis of pure silica ITQ-13 zeolite using fumed silica as silica source

Pure silica ITQ-13 (ITH) zeolite was successfully synthesized using fumed silica as silica source. Compared with the conventionally used tetraethyl orthosilicate (TEOS), application of fumed silica facilitated the gel-making process as the hydrolysis procedure was omitted. On basis of that, influences of reactant H2O/Si ratios and crystallization temperatures on the synthesis of ITQ-13, as well as the properties of the as-synthesized and calcined samples, were investigated. As evidenced by XRD, SEM, XRF, N2 adsorption, TGA and TPO-MS results, well crystallized ITQ-13 zeolites were obtained at low H2O/Si ratios (7∼8). The primary crystals of the ITQ-13 zeolites were in plate-like shape, and the plate thickness increased upon the increasing crystallization temperature. ITQ-13 samples exhibited excellent thermal stability, especially for those synthesized at high temperatures.