Hydrothermal Synthesis Of Layered Aluminosilicate Zeolite

MCM-22zeolite is a new catalysis material which contains ten and twelve member ring channels and exhibits excellent catalytic performance in many reactions. ITQ-2catalyst could be prepared by swelling and delaminating the MCM-22precursor, it could enhance the accessibility of large molecules and improve the catalytic performance.The template used by the tradition method of MCM-22zeolite synthesis is high toxicity and strong volatility, and the product is easy to aggregate. Therefore, in this paper, the research was carried on to avoid the use of toxic template in the environment and synthesize the high-scattered products. The study of samll amount of the organics and recycling for the mother liquor was performed because of the high cost and the serious environmental pollution in the process of synthesizing ITQ-2zeolite. XRD, SEM, N2physical adsorption, FT-IR and NH3-TPD technologies were used to study the characters of catalysts and draw the following conclusions:(1) Pure MCM-22zeolite could be synthesized by the acidulating template agent and the optimized conditions for the synthesis of MCM-22were obtained. The acidification of the template agent could avoid the harm of toxic template on the environment and human being effectively.(2) Under optimized conditions for TPAOH system, ITQ-2was synthesized by swelling and delaminating the MCM-22precursor with low amount of CTAB and TPAOH rapidly.(3) The effective components in the mother liquor of the ITQ-2could be separated and determined through both the hot filtration-condensation and condensation-evaporation separation methods which could ensure the stability of the recycle of the mother liquor.(4) Pure and high-scattered MCM-22zeolites were synthesized under static hydrothermal crystallization conditions by adding biomass assistant. Pure MCM-22zeolite with large surface area and high water thermal stability was synthesized under dynamic hydrothermal crystallization conditions and biomass assistant.