Abstract: The invention discloses a method for preparing maleate by selective catalytic oxidation of lignin. The method uses a heteropolyacid functionalized ionic liquid as a catalyst, and an aqueous alcohol solution as a reaction medium to achieve high-efficiency selective catalytic conversion and ring opening oxidation of biomass lignin at a reaction temperature of 110-160° C. and an oxygen pressure of 0.5-1.0 MPa for 1-6 h. The selectivity of maleate is higher than 47.83%. The yield and selectivity of a single chemical derived from the depolymerization of lignin in the present invention are much higher than the prior art, and the ionic liquid catalyst exhibits outstanding advantages such as availability of recovery and recycling through simple temperature adjustment; the reaction conditions of the present invention are mild, and the process is green and safe, easy to operate, and available for batch and continuous production.

Abstract: The invention discloses a method for preparing maleate by selective catalytic oxidation of lignin. The method uses a heteropolyacid functionalized ionic liquid as a catalyst, and an aqueous alcohol solution as a reaction medium to achieve high-efficiency selective catalytic conversion and ring opening oxidation of biomass lignin at a reaction temperature of 110-160° C. and an oxygen pressure of 0.5-1.0 MPa for 1-6 h. The selectivity of maleate is higher than 47.83%. The yield and selectivity of a single chemical derived from the depolymerization of lignin in the present invention are much higher than the prior art, and the ionic liquid catalyst exhibits outstanding advantages such as availability of recovery and recycling through simple temperature adjustment; the reaction conditions of the present invention are mild, and the process is green and safe, easy to operate, and available forbatch and continuous production.