Method for preparing titanium-containing molecular sieve used for epoxidation

Abstract

The invention discloses a method for preparing a titanium-containing molecular sieve which can be used for epoxidation. The method comprises the following steps of: (1) preparing colorless and transparent titanium tetrachloride solution at a low temperature of less than 10 DEG C, using the titanium tetrachloride as a titanium source, adding deionized water, and fully shaking to obtain 8 to 56 mass percent colorless and transparent aqueous solution; and (2) introducing the titanium into a nano pore of a mesoporous molecular sieve by an immersion method: cooling the mesoporous molecular sieve to less than 10 DEG C under the dry condition, adding 1 to 5g of mesoporous molecular sieve into 3 to 20 ml titanium tetrachloride solution and uniformly stirring, immersing at the low temperature 10 to 40 hours, drying the solution in a drying oven with the temperature of 100 DEG C, and finally roasting at the temperature of 550 DEG C for 5 to 8 hours to obtain the titanium-containing molecular sieve. The method for preparing the titanium-containing molecular sieve has the advantages of simple and convenient synthesis method, easy operation, low cost, high synthesis speed, and good repeated preparation. The synthesized material has excellent catalytic epoxidation function.

Description

technical field [0001] The invention belongs to the technical field of inorganic functional materials and fine chemical manufacturing, and mainly relates to a preparation method of a titanium-containing molecular sieve which can be used for epoxidation reaction. Background technique [0002] Titanium-silicon molecular sieves such as: TS-1 have good catalytic performance in catalyzing the oxidation reaction of olefins with aqueous hydrogen peroxide or organic peroxides. Compared with traditional oxidation processes, they have the advantages of energy saving, economy and environmental friendliness. Since titanium-silicon molecular sieve has a microporous structure, its pore size (for example: TS-1, 0.55nm; Ti-β, 0.76×0.64nm) is small, which limits its use in rings of alkenes with small molecular sizes. Oxidation reaction, for larger molecules such as methyl oleate (0.5×0.5×0.5×0.5×2.5nm), it is difficult to diffuse in its pores and be catalyzed by epoxidation, which makes its ...

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Problems solved by technology

[0003] In the preparation process of titanium-containing mesoporous molecular sieves, organic titanium such as: butyl titanate is used as the titanium source, but the high price of organic titanium will make the cost higher, and the price of titanium tetrachloride is low, but due to the tetrachloride in the preparation process The hydrolysis of titanium oxide is too fast, so that TiO is generated before Ti enters the molecular sieve framework. 2 On the other hand, although the preparation method of mesoporous materials is relatively mature, in the process of introducing heteroatoms, such as: adding heteroatoms to sol-gel will cause the channels to deform or even collapse, and the prepared catalysts have poor reproducibility

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