Direct conversion of biomass-derived carbohydrates to 5-hydroxymethylfurfural using an efficient and inexpensive manganese phosphate catalyst

Achieving high yields of 5-hydroxymethylfurfural (HMF) from carbohydrates remains a challenge today. With the aim of developing an efficient and inexpensive catalyst for the production of HMF, manganese phosphate (MnPO4) was used as the sole catalyst for the catalytic conversion of biomass-derived carbohydrates into HMF in the H2O/tetrahydrofuran (THF) biphasic reaction system. The effects of various factors, including reaction temperature, reaction time, system, and catalyst dosage on the conversion of carbohydrates to HMF were explored. An impressing HMF yield of 59% was achieved with glucose as a feedstock at 160 °C for 90 min. Meanwhile, up to 44% of HMF was also obtained with microcrystalline cellulose as a feedstock at 170 °C for 120 min. In addition, MnPO4 catalyst also displayed outstanding catalytic activities for the conversion of other biomass-derived carbohydrates including monosaccharides and disaccharides. Combined with the dissolution characteristics of the MnPO4, a possible catalytic mechanism for the conversion of carbohydrates into HMF catalyzed by MnPO4 was proposed. The catalytic approach proposed in this paper exhibited a promising potential for HMF production via optimizing the catalytic process.