Acid-activated montmorillonite-supported cesium catalyst and its application in the synthesis of aziridine from monoethanolamine

Abstract

The invention discloses an acid-activated montmorillonite-loaded cesium catalyst and its application in catalyzing the synthesis of aziridine from monoethanolamine. The carrier of the catalyst is acid-activated montmorillonite, and the composition of the active component is CsaXbOc, where X is phosphorus, iron or boron, O is oxygen, and a, b, and c are the molar ratios of Cs, X, and O. When a When =1, b=0.5~1.5, the value of c depends on a and b. The catalyst is prepared by activating the montmorillonite acid and loading the active components with an equal-volume impregnation method, and the method is simple and the conditions are controllable. The invention utilizes the acid to activate the montmorillonite to adjust the acidity of the catalyst, and the obtained catalyst is used for the intramolecular dehydration reaction of the monoethanolamine to synthesize the aziridine, which not only improves the conversion rate of the monoethanolamine, but also maintains the high selectivity of the product aziridine.

Description

technical field [0001] The invention belongs to the technical field of catalysts, and in particular relates to a catalyst for catalyzing the synthesis of aziridine from monoethanolamine. Background technique [0002] The molecular formula of aziridine is: C 2 h 5 N, also known as ethyleneimine, aziridine, aziridine and ethyleneimine, is an important intermediate in organic synthesis and is widely used in the preparation of anti-cancer drugs, insecticides, reactive dyes, etc. [0003] The initial industrial production method of aziridine is a liquid phase method, and monoethanolamine is used as a raw material to obtain aziridine through intramolecular dehydration reaction. The reaction equation is as follows: [0004] [0005] A large amount of concentrated sulfuric acid and concentrated alkali are required in this reaction, the cost is high, the yield is low, and a large amount of inorganic salt by-products with low utilization value are generated. Therefore, the gas-s...

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Problems solved by technology

Chinese patent CN103657694A reports a composite oxide catalyst composed of titanium, phosphorus, boron, alkaline earth metals and alkali metals. The selectivity of aziridine reaches 92%, but the conversion rate of monoethanolamine is only 63%.

In the prior art, the catalyst is highly acidic and prone to intermolecular condensation reactions to generate piperazine by-products, resulting in a reduction in aziridine selectivity; the catalyst is highly alkaline and prone to deamination reactions to generate by-product acetaldehyde, which further reacts with Product aziridine reacts to generate 1-aziridine base ethanol, thereby affecting the further improvement of aziridine product selectivity

The catalysts reported in current patents only use phosphide or boride to adjust the acidity. While the conversion rate is increased, the selectivity is greatly reduced, and it is difficult to obtain a high conversion rate of monoethanolamine and aziridine at the same time.

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