Bifunctional catalyst and application of bifunctional catalyst in preparation of benzil by benzoin dehydrogenation/oxidation

Abstract

The present invention relates to a bifunctional catalyst and an application of the bifunctional catalyst in preparation of benzil by benzoin dehydrogenation / oxidation. According to the catalyst, an anion exchange resin or a cation exchange resin is adopted as a carrier; a variable-valence transition metal or a rare earth metal element is bonded on the carrier in a chemical bonding manner, whereinthe binding amount of the variable-valence transition metal or the rare earth metal element is 0.5-10% of the weight of the catalyst; the metal element on the carrier is bonded with an acidic ion exchange resin or an alkaline ion exchange resin through chemical bonds, wherein the metal element on the carrier is adopted as an oxidation catalyst; under a certain reaction condition, benzoin is subjected to a dehydrogenation / oxidation process, hydroxyl is transformed into carbonyl, and the measured water is generated. The catalyst has the following advantages that: the use conditions are mild, the product is easy to separate, the catalyst can be used many times, and the like.

Description

technical field [0001] The present invention develops a catalyst for the preparation of benzil by dehydrogenation / oxidation of benzoin. The catalyst is composed of transition metal elements supported by resin. Under certain reaction conditions, the hydroxyl group on the benzoin is converted into a carbonyl group. Simultaneously generate the process of metered water. The catalyst has the characteristics of mild use conditions, easy separation of products, and repeated use. Background technique [0002] Benzil, also known as diphenyl ethylene dione, also known as dibenzoyl, bibenzoyl, is an important organic chemical raw material. It is used in the synthesis of photosensitizers, curing agents, insecticides, pharmaceuticals and various functional materials, and is also suitable for the production of printing inks for food, etc., and has broad application prospects. Domestic benzil industrial production methods usually use nitric acid as an oxidizing agent for metered oxidatio...

AI Technical Summary

Problems solved by technology

Domestic benzil industrial production methods usually use nitric acid as an oxidizing agent for metered oxidation, but the reaction is intense, and a large amount of nitrogen oxide gas is released to pollute the environment. It is harmful to human health, and a large amount of waste acid is produced after the reaction. Recycling will increase costs, and emissions will pollute the environment. ; For this situation, people have carried out extensive research in the past two decades, and the research methods reported mainly include DMSO / (COCl) 2 / CH 2 Cl 2 , (PhCH 2 Et 3 N)Br - / (PhCO) 2 o 2 / MeCN, NBS / CCl 4 Oxidation method, H 2 o 2 Oxidation method, a direct oxidation method in which a high-valent metal is used as an oxidizing agent

The main problems of these oxidation methods are: one-time consumption of oxidant, some are highly toxic, some are expensive, the reaction operation is complicated, separation and purification are difficult, and the discharge of environmental pollutants is large.

There are also literature reports that copper sulfate is used as a catalyst to complete the oxidation of benzoin in a pyridine solvent, but the reaction time is long, the conversion rate of raw materials is not high, the reaction solvent is expensive, the recovery of the catalyst is difficult, and the reaction conditions are harsh.