Method of synthesizing Ti-MWW molecular sieve

Abstract

The present invention relates to a synthesis method of Ti-MWW molecular sieve. Said method includes the following steps: uniformly mixing silicon source, titanium source, boron source, template agent, fluorine source and water to obtain colloidal material, them making hydrothermal crystallization so as to obtain Ti-MWW molecular sieve raw material powder, making said raw material powder reacte with acidic solution, roasting so as to obtain the Ti-MWW molecular sieve.

Description

technical field [0001] The invention relates to a synthesis method of Ti-MWW molecular sieve, which belongs to the technical field of inorganic chemical synthesis. Background technique [0002] Molecular sieves with MWW structure are a class of molecular sieves with sinusoidal 10-membered ring network pore system, 12-membered ring cavity and supercage pore system structure (Science, 1994, 264: 1910). The catalytically active aluminum atoms are introduced into the framework of MWW molecular sieves to form MCM-22 molecular sieves (US4,954,325). Due to the special pore structure, as an acidic catalytic active component, MCM-22 molecular sieve exhibits excellent catalytic properties such as catalytic cracking (US 4,983,276), olefin and benzene alkylation (US 4,992,606, US 4,992,615, US 5,334,795). Molecular sieves with MWW structure, as acidic catalytic active components, have been industrialized in the process of alkylation of olefins and benzene. [0003...

AI Technical Summary

Problems solved by technology

The feature of the titanosilicate is that its structural formula is: xTiO 2 ·(1-x)SiO2 2 ; X-ray diffraction spectrum of molecular sieve with MWW structure; its preparation process is, the first step, hydrothermal crystallization to prepare the MWW structure precursor containing silicon and boron, the second step, acid treatment the MWW structure precursor obtained in the previous step In the third step, the product obtained in the previous step is subjected to hydrothermal crystallization treatment together with the titanium source and template aqueous solution. In the fourth step, the product obtained in the previous step is roasted to obtain the product titanosilicate, that is, two steps are carried out. Secondary hydrothermal crystallization process, long process and high cost

[0006] From the above, it can be seen that the process of synthesizing a titanium-silicon molecular sieve with a MWW structure is complicated, the process flow is long, and the production cost is high, which is not conducive to the industrial production and application of the molecular sieve.

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