Coupled Chemical and Thermal Drivers in Microwaves toward Ultrafast HMF Oxidation to FDCA

Fast reaction rate under mild reaction conditions is highly desired in the oxidation of 5-hydroxymethylfurfural (HMF) to 2,5-furandicarboxylic acid (FDCA). Continuous control of pH and temperature is the key to accelerate the reaction rate. This work offers a binary addition method enabling continuous control of solution pH during the entire reaction period and thus expedites reaction rate in each step along the reaction path. The fluctuation of reaction temperature from binary addition is then addressed by a coupled microwave heating method. FDCA yield of >99 mol % can be achieved within 30 min under mild reaction conditions of atmospheric pressure and low temperature of <100 °C.