Preparation method and application of titanium silicalite molecular sieve catalyst

Abstract

The invention discloses a preparation method and application of a titanium silicalite molecular sieve catalyst. The preparation method comprises the following steps: 1) synthesizing a TM-HTS catalyst doped with an Ag element, namely an Ag-HTS catalyst; and 2) introducing ammonia gas into the Ag-HTS catalyst under the protection of inert gas, heating to 300-800 DEG C, and reducing for 1-5 hours. The application refers to application of the titanium silicalite molecular sieve catalyst in visible light catalytic oxidation reaction, especially application in catalytic oxidation of cyclohexene. The response wavelength of the titanium silicalite molecular sieve can be prolonged to a visible light region, and the total selectivity of 2-cyclohexenol and 2-cyclohexenone is as high as 95.5% under the condition of high conversion rate; in the absence of a solvent and an initiator, the cyclohexene is catalytically oxidized in a light path form, so that the energy consumption is reduced, the types of oxidation products of the cyclohexene are controlled, and the total selectivity of the 2-cyclohexenol and the 2-cyclohexenone is improved.

Description

technical field [0001] The invention relates to a preparation method and application of a titanium-silicon molecular sieve catalyst, and the related fields are catalysts containing molecular sieves and applications of the catalyst in catalytic oxidation of cyclohexene. Background technique [0002] At present, in the research of cyclohexene catalytic oxidation at home and abroad, organic oxidants or hydrogen peroxide and other oxidants are mostly used, and high temperature and high pressure hydrothermal method is often used in the synthesis industrial route, which leads to the production of undesirable by-products, reduces the product yield, and makes subsequent recovery and separation. The steps are complicated. Therefore, it is of great significance to carry out the research work on the visible photocatalytic oxidation of cyclohexene under the condition of no organic solvent and molecular oxygen as the only oxygen source. [0003] Titanium silica molecular sieve is a new ...

AI Technical Summary

Problems solved by technology

However, while TS-1 molecular sieve has the above-mentioned advantages, it also has some disadvantages: First, the pores of TS-1 molecular sieve are microporous, and it is difficult for reactant molecules with large sizes to enter the pores of TS-1 molecular sieve, resulting in only The active sites on the surface of TS-1 molecular sieve play a catalytic role; the second is that the content of Ti in the skeleton of TS-1 molecular sieve is limited, usually only about 2wt% in the skeleton Ti, which limits its application range

However, the response wavelength of conventional TM-HTS is insufficient, and it is difficult to be applied to reactions such as the oxidation of cyclohexene under visible light, which limits its application range.

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