Preparation method of beta molecular sieve

Abstract

The invention discloses a preparation method of a beta molecular sieve. The preparation method comprises the steps of: 1. synthesis of initial gel: mixing a silicon source, an aluminum source, a template agent, an alkaline metal source, water and a beta molecular sieve seed crystal evenly to synthesize an initial gel, wherein the silicon source is calculated in terms of SiO2, the aluminum source is calculated in terms of Al2O3, the template agent is calculated in terms of TEA<+>, the alkaline metal source is calculated in terms of Na2O, and the raw materials for synthesizing the initial gel are in the following mole ratios that: SiO2 / Al2O3=25-150:1, TEA<+> / SiO2=0.07-0.23:1, Na2O / SiO2=0.03-0.12:1, and H2O / SiO2=3.0-11.5:1, the beta molecular sieve seed crystal has a Si-Al ratio of SiO2 / Al2O3=20-100:1, and in terms of mass, the adding amount is 0%-10% of the mass of SiO2; and 2. microwave heating crystallization reaction: conducting microwave heating treatment on the initial gel preparedby step 1, controlling the heating temperature at 120DEG C-180DEG C and the heating time at 4-25h, thus obtaining a beta molecular sieve product. The method provided by the invention can synthesize the beta molecular sieve with high crystallinity and abundant pore structures by only one step, and compared with the conventional hydrothermal synthesis method, the method provided by the invention cangreatly shorten the synthesis time of the beta molecular sieve, the grain size of the molecular sieve is smaller, and the pore channels are smoother.

Description

technical field [0001] The invention belongs to the technical field of catalytic chemistry, and in particular relates to a synthesis method of beta molecular sieves. Background technique [0002] β molecular sieve is a patented product USP3308069 researched and developed by Mobil Petroleum Company of the United States in 1967. The earlier reports that β molecular sieves have excellent catalytic performance are the follow-up patents EP0159846 and EP0159847 developed by Mobil Corporation for β molecular sieves, which disclose that β molecular sieves have excellent activity for hydrocarbon cracking and isomerization. Since the 1990s, with the understanding of the crystal structure of β molecular sieve, the research on the synthesis and catalytic performance of β molecular sieve has been carried out rapidly. Excellent catalytic performance in numerous catalytic reactions in petroleum refining and petrochemical processes such as wax and photocatalysis. Because it is the only hi...

AI Technical Summary

Problems solved by technology

Adding templates to synthesize β molecular sieves is still the mainstream technology, but conventional hydrothermal synthesis has the problems of large amount of templates, high water content in the system, and low product yield.

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