Synthesis Of ZSM-5 Based On Different Diameter And Silica-alumina Ratio

In the early 1970s, Mobil Corporation developed a kind of zeolites, named ZSM-5. ZSM-5 zeolite has a unique three-dimensional porous structure, and its pore size is about 0.55 mn, possessing good thermal stability and high catalytic performance. In recent years, ZSM-5 zeolite was usually applied to catalytic cracking and shape-selective catalysis of crude oil. With the improvement of catalytic requirements, meanwhile, in order to prevent carbon deposition, the demand of ZSM-5 in nano-scale increased gradually. The aim of this research is trying to make the diameter of ZSM-5 zeolite smaller. The main results are as follows:1. The influence of silica-alumina ratio on granularityOther conditions are unchanged, just adjust silica-alumina ratio in the experiment. Firstly the molecular sieve of ZSM-5 zeolite was synthesized using hydrothermal method, and then tested by a series of means, such as X-ray powder diffraction (XRD), Scanning electron microscope (SEM), Nitrogen adsorption desorption isotherms (BET), Fourier infrared absorption spectroscopy (Py-IR). Last, the effect of silica-alumina ratio on molecular sieve of ZSM-5 zeolite was analyzed comparatively.2. The influence of dosage amount of NaCl on graininessOther conditions remain constant, adjust the dosage amount of NaCl, and in the meantime synthesize the molecular sieve of ZSM-5 zeolite based on hydrothermal synthesis. Then according to the particle size of the molecular sieve, the impact of dosage amount of NaCl on the molecular sieve of ZSM-5 zeolite was explored.3. The influence of alkalinity on particle sizeAll other things are equal, adjust the dosage amount of NaOH, and also change PH, from 7 to 14. Taken the variation rule of the synthesized graininess of molecular sieve of ZSM-5 zeolite into account, the appropriate range of pH was obtained for small particle size of the molecular sieve of ZSM-5 zeolite.4. The influence of crystal seed on granularityOther synthesis conditions keep invariant, change the dosage amount of crystal seed, make a comparative analysis for the synthesized graininess of molecular sieve of ZSM-5 zeolite, then, the influence of the dosage amount of crystal seed on graininess was analyzed.5. The influence of distilled water on granularityOther synthesis conditions contain constant, the molecular sieve of ZSM-5 zeolite was synthesized through hydrothermal syntheses based on different dosage amount of distilled water. By contrast with the particle size achieved in the different experiments, the influence of distilled water on granularity of the molecular sieve of ZSM-5 zeolite was confirmed.