In-situ supported forming preparation method of titanium silicon molecular sieve composite catalyst

Abstract

The invention relates to an in-situ supported forming preparation method of titanium silicon molecular sieve composite catalyst. The method comprises the steps: (1) introducing a porous system into a TS-1 hydrothermal synthesis system of an MFI topological structure consisting of a silicon source, a titanium source, a template agent, a complexing agent and an alkali source; (2) separating out crystal nucleus from TS-1 on the surface and in pores of the porous material after aging, and loading the crystal nucleus onto the porous material in an in-situ growth manner to obtain an intermediate product 1; (3) crystallizing the intermediate product 1 to obtain a mixture of TS-1 composite catalyst, and separating and drying the mixture to obtain an intermediate product 2; and (4) roasting the intermediate product 2 in a N2 atmosphere to obtain the TS-1 composite catalyst. According to the prepared TS-1 composite catalyst, TS-1 is firmly combined with the porous material, the mechanical strength is high, and the abrasion resistance is good; the TS-1 is in-situ formed in a porous material carrier, so that the specific surface area is increased, and the catalytic efficiency is improved; the process is simple, and the production cost is low; the catalyst is large in particle size and easy to separate, and the service life is prolonged.

Description

technical field [0001] The invention relates to a preparation method of a catalyst, in particular to a preparation method of a titanium-silicon molecular sieve composite catalyst, belonging to the technical field of chemical synthesis. Background technique [0002] Titanium silicate molecular sieve (TS-1) is a commonly used catalyst in the field of chemical synthesis, and TS-1 is usually prepared by hydrothermal synthesis. However, TS-1 prepared by the hydrothermal synthesis method is a fine powder with a grain size ranging from 0.1 to 5 μm, which is difficult to separate from the reaction medium, and cannot meet the requirements of industrial equipment for catalyst strength, life, shape, etc. Therefore, , The molding process of TS-1 is an indispensable step for its industrial application. The traditional TS-1 molding method is secondary molding. Generally, the crystallization solution of the TS-1 precursor synthesized by hydrothermal treatment is washed, centrifuged, roast...

AI Technical Summary

Problems solved by technology

The particle size of TS-1 before molding is small, the loss in the reaction is very serious, and the life of the catalyst is very short, only 34h

The service life of the microsphere TS-1 catalyst prepared by spray molding is increased to more than 148h, but its catalytic performance in the ammoximation reaction of cyclohexanone will be greatly reduced

[0003] Based on the above preparation methods, the prior art TS-1 catalyst molding mainly has the following defects: poor stability, overall low catalytic efficiency, weak mechanical strength, and it is difficult to be widely used in industrial production

The extrusion molding method requires high technical requirements and the spray drying molding method has high costs, which limit the application of the catalyst molding method, which in turn affects the production and application of the TS-1 catalyst