Synthesis and characterization of Ce-ZSM-5 zeolite membranes

摘要

The effects of synthesis parameters on the property of Ce-ZSM-5 zeolite membrane grown onto porous alpha-alumina supports were investigated.The zeolite membranes synthesized were characterized by XRD,DTA/TG,FT-IR,SEM,EDS and single gas permeation.Orthogonal test indicate,aging at lower temperature and longer stirring time were preferred for Ce-ZSM-5 zeolite membrane.Lower alkalinity and higher Ce_2O_3/SiO_2 favor the formation of pure Ce-ZSM-5 structure.Higher alkalinity and lower SiO2/Ce2O_3,impurities such as quartz and cerium oxide,which hinder the Ce-ZSM-5 formation were easily produced.Under optimum synthesis conditions,the permeances for H_2,N_2,CH_4,CO_2 were 4.73 x 10~(-6),1.56 x 10~(-6),1.51 x 10~(-6) and 1.36 x 10~(-6) mol/m~2 s Pa,respectively;the ideal selectivity of membrane at room temperature for H_2/CO_2,H_2/N_2,H2/CH4 were 3.13,3.03,3.48,respectively.