Synthesis and Characterization of Small Crystals NaY Zeolite with High Silicon

Small crystals NaY zeolite with high silicon was successfully synthesized via a two-stage temperature crystallization program, without adding any organic additives. While the effect of low temperature crystallization time and the alkalinity on the crystal size and SiO2/Al2O3 ratio of NaY zeolite were investigated. The as-synthesized samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier Transform Infrared (FT-IR) spectroscopy, N2 adsorption, 29Si MAS NMR and thermogravimetric TG measurements. NaY zeolite, with crystal size about 100 nm and SiO2/Al2O3 ratio about 5.3, is obtained. It possesses high surface area and some amount of mecropores, and the decomposition temperature is higher than 1000 °C. The crystal size and SiO2/Al2O3 ratio of as-synthesized NaY zeolite depend on low temperature crystallization time and the alkalinity.