Preparation Of MFI Zeolite Membranes Structured Catalyst

Structured Catalysts are a kind of monolithic catalysts, and metallic based structured catalysts are more and more applied widely in the field of heterogeneous catalyst and pollution control with well mechanicalstrength and thermal conductivity. Particularly, zeolite grown on the structured substrate make up zeolite membranes structured catalysts,which not only have the quality of catalyst and separatation,but also have the advantages of structured Catalysts and then broadened out the application area of zeolite membrane.However, in the actual operation, membrane-substrates bond strength not always meet the demand, crack,even drop as result of the significant differences significant differences between metallic substrate and zeolite membrane.This study addresses some of the existing problems in preparation of zeolite membrane structured catalyst. Firstly, ZSM-5 membranes are prepared on stainless steel with the template of TPABr, TPAOH and non-template. The experiment results show that the zeolite membranes are prepared by the different template and non-template successfully, but the feature and direction of growth of these membrane exist significant difference, which have a greater impact on the bonding strength between substrate and membrane. The residual rates after heat shock test are 82.63%,85.96%,84.13%respectively and which after ultra-sonic oscillation test are 66.72%,88.38%,86.22%.Secondly, Silicalite-1 zeolite membranes are prepared by seeding technique. The seed layer are prepared by three kinds of dip-coating metod,and on the surface of which Cu are electroplated with the purpose of anchoring the seed layer on the surface of stainless steel.The study investigate the effects of different method of seed layer preparation on seed layer.The experiment shows that the seed layer prepared by the method C distributes homogeneously,bonds well and the Silicalite-1 membranes grown on the seed layer have the well bonding strength with the stainless steel substrate.The residual rates after heat shock and ultra-sonic oscillation test are 85.27%,89.73%respectively.Finally, Silicalite-1 seed layer is prepared by in situ hydrothermal synthesis,and then Cu are electroplated on the seed layer with the purpose of anchoring the seed layer on the surface of stainless steel,afer which Silicalite-1 zeolite membranes are secondary grown on the seed layer. The study investigates the influences of electro-deposition conditions.The suitable condition of electro-deposition is the concentration of electro-deposition is 0.5mol/L H3BO3 and 0.9 mol/LCuSO4, the anode is carbon, the cathode is the substrate, the distance bween the two pole is 2cm, the voltage is 3V, the time is 3min.And then investigates the influences of synthesis conditions on Silicalite-1 zeolite membrane, and find out the suitable condition is 24h under 175℃. The residual rates after heat shock and ultra-sonic oscillation test are 94.24%,95.66% respectively.