Study on catalytic conversion of cellulose to 5-Hydroxymethyl furfural by directional degradation in deep eutectic solvent

Abstract

The direct conversion of microcrystalline cellulose (MCC) degrading into 5-hydroxymethyl furfural (5-HMF) was studied using four synthetic deep eutectic solvents (DESs) as solvents and choosing four metal chlorides as catalysts. The factors that affected the yields of the products, such as the type of DESs, the type and dosage of catalysts, the ratio of DESs to MCC, and reaction temperature were researched. It was found that the DES synthesized from oxalic acid and choline chloride (O-DES) and SnCl4 showed the better performance. The highest 5-HMF and glucose yields of 11.0% and 22.0% were obtained, respectively, for a reaction carried out at 160 °C for 90 min in O-DES (the ratio of it to MCC was 25:1) using 1.42 wt% SnCl4 as the catalyst. As a new type of dissolution and catalysis system, the DESs were not only cheaper but also easy to obtain. Most importantly, the realization of the concept of green chemistry was achieved in this study.