Zeolite molecular sieve as well as preparation method and application thereof

Abstract

The invention discloses a zeolite molecular sieve as well as preparation method and application thereof, and belongs to the field of chemical technology. In the invention, V-Si-ZSM-22 zeolite molecular sieves different in vanadium content (0-25%) are synthesized by an ionic liquid dry glue method, wherein the vanadium species exists mainly in a form of chained poly VO3<-> and is connected with a zeolite framework through a vanadium-oxygen bond to be applied to a rapid hydroxylation reaction of arene; in an ideal condition that the substrate and hydrogen peroxide have an equal molar ratio, a high yield of phenol products is obtained within a reaction time of 30 seconds. The catalyst adopted in the invention is easy to prepare; the reaction time is extremely short, and thus the reaction is efficient and energy-saving; the yield of phenol products is high, and fewer byproducts are generated; with the hydrogen peroxide as an oxidizing agent, the economic cost and environmental cost are low; the product is easily separated from the catalyst, and the aftertreatment is simple; the catalyst is easy to use repeatedly and thus is green and environmentally friendly, and has a very important application prospect.

Description

technical field [0001] The invention relates to the field of chemical technology, in particular to a zeolite catalyst, a preparation method and an application thereof. Background technique [0002] Aromatic compounds with hydroxyl groups on the benzene ring (such as phenol and cresol, etc.) are an important class of organic intermediates, and they are widely used as precursors of dyes, polymers, plastics, drugs and pesticides. body. However, the preparation of phenolic compounds has the disadvantages of high energy consumption, environmental pollution and overoxidation in the process of industrial production, and the yield of phenolic products produced by the reaction is very low. The direct hydroxylation reaction of benzene ring in hydrogen peroxide oxidation has always been the focus of attention. However, in order to design an effective catalytic system in this type of reaction, the main challenges are as follows: (1) for the benzene ring (especially For benzene) inert ...

AI Technical Summary

Problems solved by technology

But for the preparation of phenolic compounds, in the process of industrial production, there are defects of high energy consumption, environmental pollution and overoxidation, and the yield of phenolic products generated by the reaction is very low

The direct hydroxylation reaction of benzene ring in hydrogen peroxide oxidation has always been the focus of attention. However, in order to design an effective catalytic system in this type of reaction, the main challenges are as follows: (1) for the benzene ring (especially For benzene) inert sp 2 The activation of the C-H bond is very difficult; (2) the excessive oxidation of some phenolic products leads to a decrease in yield and selectivity; (3) in the oxidation reaction of aromatic compounds, the sp on the side chain 3 C-H bond than sp on aromatic ring 2 The C-H bond is more easily oxidized, because the bond dissociation energy of the former is much lower than that of the latter, so it is easier to be oxidized, making the reaction difficult to generate phenolic products

[0003] When the molar ratio of hydrogen peroxide and aromatic compound substrate is 1, the yield is low and the selectivity is low, and the reaction generally requires more than ten hours of reaction time to complete the reaction

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