Cobalt-based catalyst for generating ester by alcohol oxidation, and preparation method and application of cobalt-based catalyst

Abstract

The invention belongs to the technical field of liquid phase oxidation, and discloses a cobalt-based catalyst for generating ester by alcohol oxidation, and a preparation method and application of the cobalt-based catalyst. The cobalt-based catalyst mainly comprises the following elements in percentage by weight: 27.0-50.0 percent of cobalt, 45.0-60.0 percent of carbon and 0.5-20.0 percent of nitrogen, wherein the particle diameter of cobalt nano particles in the cobalt-based catalyst is 5-40 nm. The cobalt-based catalyst is prepared in a pyrolysis mode in an inert atmosphere with ZIF-67 as a precursor. In the presence of the cobalt-based catalyst, alkaline aids are not added in the normal-temperature and normal-pressure atmospheric environment, and two alcohols react to prepare ester compounds. The cobalt-based catalyst is easy to synthesize in quantity, and is magnetic and recyclable. A method for catalyzing alcohol oxidation to generate ester in the presence of the cobalt-based catalyst has the advantages of low cost, simplicity in operation, environment friendliness, mild reaction condition, easiness in product separation and the like.

Description

technical field [0001] The invention belongs to the technical field of liquid-phase oxidation, and relates to a cobalt-based catalyst, in particular to a cobalt-based catalyst used to oxidize alcohols to generate esters, a preparation method and application thereof. Background technique [0002] As one of the most important functional groups in the field of organic chemistry, ester groups are widely found in various fine chemicals, natural chemicals, and polymers. They can be used as food additives or cosmetic additives, and some esters can be used in medicine and other fields. For example, methyl esters are widely used as flavoring agents, solvents, diluents and extractants, etc., and have very high commercial value. Aromatic esters are often used as intermediates in organic synthesis due to their versatility, and are widely used as microcrystalline polymers, cosmetics, and pharmaceuticals. [0003] At present, researchers mainly synthesize ester compounds through four rou...

AI Technical Summary

Problems solved by technology

At the end of the last century, acid derivatives such as acid chlorides or anhydrides were mainly synthesized by reacting with alcohols, but this reaction pathway would generate some unwanted by-products, and cause waste of resources and environmental pollution (Larock R C, "Comprehensive organic transformations: a guide to functional group preparations”, New York: Wiley-VCH.1999)

Around 2005, it was found that a more direct synthesis route is to use transition metal catalysts to catalyze the reaction of halogenated aromatic hydrocarbons and alcohols to form ester compounds, but this involves the carbonylation of halogenated aromatic hydrocarbons, and the reaction conditions are relatively harsh and require high temperature. CO atmosphere and high pressure, the reaction system is not environmentally friendly (halogenated aromatic hydrocarbons pollute the environment)

For the reaction substrates, aromatic alcohols have higher activity due to the existence of active groups such as benzene rings, and the reactivity of aliphatic alcohols and heterocyclic alcohols is not ideal, and most of them require harsher conditions than aromatic alcohols to proceed.

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