Electrochemical Valorization of Furfural to Maleic Acid

Maleic acid (MA) is a platform chemical used for various industrial processes. In this study, a new electrochemical oxidation method that can convert furfural, which is one of the most important CS platform chemicals derived from cellulosic biomass, to MA is reported. This method can produce MA in aqueous media under ambient temperature and pressure without the use of oxidizing agents. The use of acidic media, which promotes opening of the furan ring during oxidation, was critical for the formation of MA. PbO2, MnO2, and Pt, which are stable in acidic solutions under strongly oxidizing potentials, were investigated as anodes for furfural oxidation. The results showed that PbO2 is the only catalyst that can convert furfural to MA as the major product. It was also revealed that the electrochemical conversion of furfural to MA proceeds with 2-furanol as an intermediate.