Catalyst for synthesizing methylal by methanol through liquid-phase one-step oxidation as well as preparation method and application method of catalyst

Abstract

The invention provides a catalyst for synthesizing methylal by methanol through liquid-phase one-step oxidation as well as a preparation method and an application method of the catalyst and relates to the technical field of chemical synthesis. The catalyst provided by the invention is a copper halide/ionic liquid composition with the mol ratio 1 to (0.5 to 10), wherein a the cation of ionic liquid is selected from one or more of an iminazole type ion, a pyridine type ion and a quaternary ammonium salt ion; an the anion of the ionic liquid is selected from one or more of a halogen ion, a nitrate ion, a bisulfate ion, a dicyanamide ion, a trifluoromethanesulfonate ion, a tetrafluoroborate ion, a hexafluorophosphate ion and a bistrifluoromethanesulfonimide ion. According to the catalyst provided by the invention, a catalysis system is formed by mixing copper halide and the ionic liquid; compared with a copper halide catalyst in the prior art, the selectivity of the methylal is improved to 87 percent or more, even the selectivity of part of reagents even reaches 90 percent or more; compared with a CuCl/oxime compound catalyst, the catalysis system has smaller toxicity, is more environmentally friendly and has better stability; the requirements for green chemical engineering by an existing production trend are met.

Description

technical field [0001] The invention relates to the field of chemical synthesis, in particular to a catalyst for synthesizing methylal by one-step oxidation of methanol in a liquid phase, and a preparation method and use method thereof. Background technique [0002] Methylal (also known as dimethoxymethane, dimethoxymethane, DMM for short), is one of the main downstream products of methanol. It has the characteristics of low toxicity, good solubility, low boiling point, and fast volatilization. It can be widely used in rubber, Medicine, cosmetics, paint and other fields, especially for the synthesis of DMM, a diesel additive with great application prospects n . DMM n With higher oxygen content and cetane number, it can greatly improve the combustion performance of diesel and reduce CO in combustion exhaust x and NO x It is an ideal environmental protection product. Therefore, the development of methylal catalysts and processes has attracted the attention of researchers....

AI Technical Summary

Problems solved by technology

[0006] The invention provides a catalyst for synthesizing methylal by one-step oxidation of methanol in liquid phase and its preparation method and use method, in order to solve the technical problems of low selectivity of existing catalysts, incapable of repeated use, extremely difficult recovery, and environmental pollution