Aerobic oxidation of 5-[(formyloxy)methyl]furfural to 2,5-furandicarboxylic acid over MoCuOx catalyst

Abstract Generally, 5-hydroxymethylfurfural (HMF) is used as feedstock to produce 2,5-furandicarboxylic acid (FDCA). Whereas, its poor stability in alkaline environment results in low yield of FDCA. By contrast, 5-[(formyloxy)methyl]furfural (FMF), a novel platform compound derived from HMF, with higher thermal and alkaline stability than HMF, is more promising to replace HMF as substrate for the production of FDCA. In this study, FMF was successfully converted into FDCA over MoCuOx by using NaClO as oxidant, undergoing 2,5-diformylfuran (DFF) and 5-hydroxymethylfuran-2-carboxylic acid (HMFCA) as intermediates. Under optimization condition (30 min, 40 °C), 100% yield of FDCA was obtained. Furthermore, it was also demonstrated that the yield of FDCA up to 90% was gained in 5 wt % FMF concentration. Higher oxygen species mobility and lattice oxygen ratio endowed MoCuOx excellent catalytic activity. The synergy of Mo and Cu species in MoCuOx ensured an efficient conversion of HMF to FDCA through synergistic redox couple of Mo6+/Mo5+ and Cu2+/Cu+.