The Synthesis And Catalytic Performance Of Zsm-5 Zeolite Nano Research

In this paper, nanosized ZSM-5 zeolite with varied SiO2/Al2O3 ratio was successfully prepared in the absence of organic template based on the use of precrystallized seed precursor solution. The products were inspected by means of XRF, XRD, nitrogen adsorption, NH3-TPD, SEM,27Al MAS NMR. We have evaluated three different preparetion method aimming at the identification difference of nanosized ZSM-5 zeolite with acid and structure properties.The influence of solvent, reaction temperature, reaction pressure, space velocity and mole ratio of naphthalene and methanol on alkylation process was investigated to optimize the technological conditions. The catalytic performance of nanosized ZSM-5 zeolite with the different synthesitic method was studied, under the optimum condition,that is, reaction temperature is 400℃, reactionpressure is 3MPa,WHSV= 0.5h-1,NAPH:CH3OH:1,2,4-TMB=1:2:8.By changing the condition of the template-free synthetic method, nanosized and microsized ZSM-5 zeolite were successfully synthesized. Through selecting the naphthalene and methanol alkylation reaction as a probe to investigate the structure,acidity and catalytic performance between nanosized ZSM-5 and microsized ZSM-5 zeolite.Hydrothermal parameters of nanosized ZSM-5/MCM-41 composite material by with nanosized ZSM-5 zeolite primary and secondary building unite as silica-alumina source were investigated. The ratio of mesoporous and microporous distribution were modulated by changing treatment conditions. Catalytic performance of the alkylation of NAPH were carried out over the synthetic molecular zeolite.The results showed that 2,6-DMN selectivity was increased, indicating that the shape-selective of molecular sieve was improved as the formation of mesoporous structure in the nanosized bimicro/mesoporous ternary composite molecular sieve.