A kind of preparation method of mesoporous ZSM-5 zeolite

Abstract

The invention discloses a preparation method of mesoporous ZSM-5 zeolite. The preparation method comprises the following steps: 1) allyl glycidyl ether and dimethyl diallyl ammonium are uniformly mixed, a sodium persulfate aqueous solution with mass concentration being 10-30% is added, the materials are uniformly stirred and heated to the temperature of 60-90 DEG C, and then a polymerization is carried out for 2-8 hours, and cooling is carried out to obtain a copolymer; 2) aluminum sulfate, concentrated sulfuric acid and deionized water are prepared to an uniform solution; 3) water glass, deionized water and the copolymer obtained in the step 1) are mixed, a mixture is continuously stirred for 0.5-3 hours, then the solution prepared in the step 2) is slowly added while rapid stirring, andthe materials are continuously stirred for 1-6 hours to obtain an uniform gel; and 4) the above gel is transferred to a high-pressure reaction vessel for crystallization, the crystallized products aresubjected to pumping filtration and washed to neutrality, and then the crystallized products are dried and roasted to obtain the mesoporous ZSM-5 zeolite. The prepared mesoporous ZSM-5 zeolite contains a lot of meso-structures, cost of raw material is low, operation is simple and easy, no special requirement is generated on equipment, and the method is suitable for industrial production and application.

Description

technical field [0001] The invention belongs to the field of zeolite molecular sieve synthesis, and relates to a method for preparing mesoporous ZSM-5 zeolite by a template method. Background technique [0002] ZSM-5 zeolite is a high-silica microporous zeolite with a three-dimensional intersecting channel system first synthesized by Mobil Corporation of the United States in 1972. Because of its good thermal stability, hydrothermal stability and shape-selective catalytic performance, it is widely used in the field of petrochemical industry. However, due to the small pore size of ZSM-5 zeolite (0.54 nm×0.56 nm), on the one hand, it is difficult for macromolecules to enter the pores; its scope of application. [0003] Recent studies have shown that introducing mesopores into microporous zeolite crystals can effectively improve the mass transfer efficiency and catalytic activity of zeolite materials for hydrocarbon molecules. Among them, the template method is an important p...

AI Technical Summary

Problems solved by technology

However, the use of aminosilane and polyammonium group surfactants as mesoporous soft templates is expensive, and the synthesis cost is high, which is difficult to accept for industrial production, and the above synthesis methods all use tetrapropylammonium hydroxide (TPAOH) as microporous templates , tetraethyl orthosilicate (TEOS) is the silicon source, which further increases the synthesis cost

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