Process for producing titanium-silicon zeolite microcapsule

Abstract

The invention relates to a method for preparing titanium silicalite microcapsules, and mainly solves the problems in the prior art, for example, the content of titanium in TS-1 molecular sieve is low, the TS-1 molecular sieve is not treated with alkali, and when the ZSM-5 molecular sieve is modified by alkali treatment, the crystallization degree is low and the microcapsule with more than 100 nm cavities and having a shell-like structure on the surface is not obtained. In order to overcome the problems, the technical scheme is as follows: the titanium silicalite microcapsules are obtained by treating TS-1 crude powders (the Si / Ti molar ratio (calculated as SiO2 / TiO2) ranges from 20 to 500 and the particle size ranges from 0.4 Mum to 20 Mum) with 0.4 mol / L to 5.0 mol / L of a solution of at least one alkali selected from sodium hydroxide, magnesium hydroxide, potassium hydroxide, calcium hydroxide, sodium carbonate and sodium bicarbonate, at a temperature ranging from 20 DEG C to 90 DEG C for a time period ranging from 1 hour to 48 hours; and the volume of cavities with a size in the range from 100nm to 160nm accounts for 20% to 70% of the total volume of cavities with a size more than 2 nm. The titanium silicalite microcapsules are applied to the industrial production of catalytic oxidationof macromolecules.

Description

technical field [0001] The invention relates to a preparation method of titanium silicalite microcapsules. Background technique [0002] Titanium-silicon molecular sieve is a new type of catalytic material developed in the past ten years. It can catalyze various organic oxidation reactions with high activity and high selectivity under normal pressure and low temperature without causing environmental pollution. It is a new type of catalyst with the characteristics of "atom economy" in the field of green chemical technology in the 21st century. TS-1 has a titanium-containing heteroatom molecular sieve with an MFI structure, and has both the catalytic effect of titanium and the type-selective effect of ZSM-5 molecular sieve (Zhao Peiqing, Peng Zhiguang, Xia Chungu, Molecular Catalysis, 2006, 4:322). The researchers believe that the main factor affecting the catalytic oxidation activity of TS-1 molecular sieve is the content of framework titanium. Too much titanium source in th...

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Problems solved by technology

[0003] The technical problem to be solved by the present invention is that there is low titanium content in TS-1 molecular sieve in the prior art, and there is no mention of carrying out alkali treatment to TS-1 molecular sieve, but there is low crystallinity when modifying ZSM-5 molecular sieve with alkali treatment method , the problem that the cavity above 100nm cannot be formed and the surface layer has a shell-like structure microcapsule, and a new preparation method of titanium silicalite microcapsule is provided