Method for synthesizing 4-methylmorpholine N-oxide based on O2 oxidation catalyzed by ruthenium/nitrogen-doped porous carbon

Abstract

The invention discloses a method for synthesizing 4-methylmorpholine N-oxide based on O2 oxidation catalyzed by ruthenium / nitrogen-doped porous carbon. According to the invention, under the conditionsof a pressure of 0.4-1 MPa and a temperature of 60-90 DEG C, ruthenium / nitrogen-doped porous carbon is used as a catalyst to catalyze a reaction of 4-methylmorpholine with O2 to synthesize 4-methylmorpholine N-oxide, wherein reaction time is 4-8 hours, and the amount of the used catalyst is 0.5 to 5 wt% of the mass of a reaction solution. The method of the invention overcomes the problems of large energy consumption in subsequent separation and wastewater pollution in conventional processes for using synthesizing 4-methylmorpholine N-oxide through H2O2 oxidation. The invention also provides amethod for preparing the ruthenium / nitrogen-doped porous carbon catalyst. The catalyst effectively mildens reaction conditions and improves the activity of 4-methylmorpholine N-oxide synthesized through O2 catalytic oxidation.

Description

technical field [0001] The invention belongs to the technical field of catalytic oxidation synthesis, in particular to a catalyst based on ruthenium / nitrogen doped porous carbon 2 A method for the oxidative synthesis of N-methylmorpholine oxide. Background technique [0002] N-methylmorpholine oxide is an important fine chemical, which is used industrially as a cellulose solvent for the production of superior performance, green and renewable Lyocell fibers. It is understood that the production of 1 ton of Lyocell fiber consumes 64 kilograms of N-methylmorpholine oxide, and the market price of N-methylmorpholine oxide is as high as 30,000 yuan / ton. It can be seen that the development of an efficient synthesis process of N-methylmorpholine oxide has obvious economic benefits, and it also provides raw material support for the rapid development of Lyocell fibers in my country, which is of great practical significance to the development of the textile industry. [0003] At pres...

AI Technical Summary

Problems solved by technology

But the main problem in this technique is: (1) to obtain the N-methyl morpholine oxide of high yield often need to add excessive H 2 o 2 , resulting in a large loss of oxidant; (2) in this synthesis process, on the one hand, the synthesis reaction and H 2 o 2 The decomposition reaction will produce a large amount of water, and on the other hand, due to the use of 30% H 2 o 2 , so that a large amount of moisture will also be brought into the raw material, increasing the separation and purification pressure of subsequent vacuum distillation and azeotropic rectification, and the long-term rectification operation will also have an impact on the quality of N-methylmorpholine oxide; (3) This process will produce more waste water and increase the cost of waste water treatment

And O 2 Oxidative synthesis of N-methyl morpholine oxide has relatively harsh reaction conditions, difficult catalyst recovery, and many side reactions, resulting in low yields of N-methyl morpholine oxide. It is necessary to develop high-efficiency heterogeneous catalysts to ease the reaction conditions, improve catalytic activity and selectivity, and solve the problem of difficult catalyst recovery

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