Synthesis and Characterization of Aluminium-free MFI-type Cobaltosilicates using Hydrothermal Method

MFI-type Cobaltosilicate zeolites with different Si/Co ratio were synthesized by hydrothermal method using silicic acid and sodium tetraborate decahydrate as starting materials. A highly crystalline MFI zeolite structure was formed under pH=13 in several days. The effect of several parameters including gel composition and pH on the crystallization of zeolites was systematically studied. Direct evidence of the incorporation of Co in the zeolite framework sites was observed by performing structure parameter refinements, and supported by data collected from other characterization techniques such as: X-ray diffraction (XRD), scanning electron microscopy (SEM), and Fourier transform infrared spectroscopy (FT-IR). The experimental results show that [Co]-MFI molecular sieves were successfully synthesized.