METHOD FOR PREPARING MALEATE BY SELECTIVE CATALYTIC OXIDATION OF LIGNIN

摘要

Disclosed is a method for preparing a maleate by a selective catalytic oxidation of lignin. The method, by using a heteropolyacid functionalized ionic liquid as a catalyst and an alcohol-water solution as a reaction medium, achieves efficient selective catalytic conversion and ring-opening oxidation of biomass lignin under the conditions of a reaction temperature of 110-160°C, a reaction time of 1-6 h, and an oxygen pressure of 0.5-1.0 MPa, and the selectivity for the maleate is 47.83% or higher. The yield and selectivity of a single chemical derived from depolymerization of lignin in the present invention are much higher than those of the prior art technologies, and the method of the present invention has significant advantages such as the ionic liquid catalyst can be recovered and recycled by means of simple temperature adjustments, etc. In the present invention, the reaction conditions are mild, the process is environmentally friendly and safe, the operation is simple, and batch production and continuous production can be achieved. The present invention provides a new environmentally friendly approach for preparing bulk chemicals such as maleates from reproducible raw materials such as lignin.