Synthesis by Two-Step Crystallization Method and Characterization of L/ZSM-5 Composite Zeolite

L/ZSM-5 composite zeolite was synthesized by two-step crystallization procedure.The effects of crystallization factors during the second step of two-step crystallization procedure,such as n(SiO2)/n(Al2O3),crystallization time,different kinds of aluminum sources,on the formation of L/ZSM-5 composite zeolite were investigated.The synthesized samples were characterized by X-ray powder diffraction(XRD),infrared spectroscope(FT-IR) and scanning electron microscope(SEM).The results showed that the synthesized sample was L/ZSM-5 composite zeolite.The best synthesis conditions were the crystallization temperature of 150℃,crystallization time of 36 h and the molar ratio of SiO2 to Al2O3 of 45.