Synthesis of ZSM-5 Zeolite with High Molar Ratio of Silica to Alumina by Hydrothermal Crystallization Method with Template

ZSM-5 zeolites with high molar ratio of silica to alumina were synthesized by hydrothermal crystallization method from industrial grade water glass and aluminium sulfate with butylamine as the template.The effects on crystallization products were investigated in different preparation factors such as crystallization time,crystallization temperature,silica-alumina ratio,pH value of synthesis system and the amount of template.The as-synthesized samples obtained from optimum conditions were characterized by X-ray diffraction,FT-IR,Nitrogen adsorption-desorption technique,nuclear magnetic resonance and scanning electron microscopy.The results showed that the optimum synthesis conditions are: The optimum synthesis conditions of ZSM-5 zeolites were listed as follows: crystallization time is 36 h,crystallization temperature is 170 ℃,silica-alumina ratio is 200,pH value is 11.0 and the molar ratio of template to silica is 0.2.The ZSM-5 zeolites with grain size about 5 μm × 15 μm have a relative high degree of crystallinity and large specific surface area(335 m2/ g).The framework silica to alumina ratio was more than 100.