Aftertreatment method of TS-1 titanium silicalite molecular sieve

Abstract

The invention creates and provides an aftertreatment method of a TS-1 titanium silicalite molecular sieve, wherein the mixed solution of strong acid and hydrofluoric acid is used for carrying out a modification treatment on the TS-1 titanium silicalite molecular sieve, and thus non-framework titanium in a molecular sieve system can be effectively removed and the surface structure of the molecular sieve can be improved; the improved TS-1 titanium silicalite molecular sieve has a higher catalytic activity and a longer catalysis life.

Description

technical field [0001] The invention belongs to the technical field of petrochemical catalysis, and in particular relates to a post-treatment method of a TS-1 titanium-silicon molecular sieve with an MFI structure. Background technique [0002] TS-1 titanium-silicon molecular sieve is a new type of titanium-silicon molecular sieve with excellent directional oxidation catalytic performance formed by introducing the transition metal element titanium into the molecular sieve framework with MFI structure. It not only has the catalytic oxidation of titanium, but also has the shape-selective effect of MFI and excellent stability, has excellent oxidation and specific selectivity, and can be widely used in the oxidation of organic substances such as benzene, phenol, alcohols, ethers, etc. Reacting. At present, cyclohexanone ammoximation and propylene epoxidation have been industrialized. In addition, the green catalytic system composed of TS-1 titanium silicon molecular sieve and h...

AI Technical Summary

Problems solved by technology

However, because the Ti-O bond is longer than the Si-O bond, it is more difficult for titanium atoms to enter the framework, so the TS-1 synthesized by the current synthesis method will produce non-framework titanium and have a negative impact on TS-1

First of all, non-framework titanium itself does not have catalytic oxidation activity but it will cause a large amount of decomposition of hydrogen peroxide, which will lead to a decrease in the catalytic performance of TS-1; secondly, the content of non-framework titanium is difficult to control, which leads to the stability of the activity of titanium silicon molecular sieves Poor performance, which restricts the industrial application of TS-1

[0004] In order to reduce the non-skeletal titanium to improve the performance of molecular sieves, many researches on the modification of TS-1 mainly use the modification of inorganic base or organic base to generate holes in TS-1 to promote the diffusion of reactants and products. This method often requires a secondary crystallization process, which easily leads to the secondary growth of the prepared TS-1 particles, which is not conducive to the effective control of the TS-1 particle size