Efficient synthesis of bio-monomer 2,5-furandicarboxylic acid from concentrated 5-hydroxymethylfurfural or fructose in DMSO/H2O mixed solvent

Abstract

The conversion of concentrated 5-hydroxymethylfurfural (HMF) or fructose to 2,5-furandicarboxylic acid (FDCA), a renewable alternative to petroleum-derived terephthalate acid, is highly desirable but challenging for FDCA production in an industrial scale. In this contribution, DMSO/H2O mixture was demonstrated as an effective medium for the production of FDCA from high concentration of HMF or fructose. For example, FDCA yield up to 93% was achieved at 10 wt% HMF concentration in DMSO/H2O over commercially available Ru/C (2 equiv. NaHCO3, 130 °C, 4 MPa O2 and 12 h). Furthermore, an overall FDCA yield of 65% was achieved from concentrated fructose (19 wt%) through a facile two-step process. Notably, it is so far the highest HMF or fructose concentration employed for FDCA formation. As compared to pure water or DMSO, DMSO/H2O mixed system is able to stabilize HMF in an alkaline environment, which allows the efficient oxidation of HMF at high concentrations.