Magnetic lignin-derived carbonaceous catalyst for the dehydration of fructose into 5-hydroxymethylfurfural in dimethylsulfoxide

Abstract A magnetic carbonaceous catalyst was prepared by a simple and inexpensive impregnation–carbonization–sulfonation process using the enzymatic hydrolysis lignin residue as a precursor. The resulting catalyst possessed a porous structure with a high surface area and contained Fe 3 O 4 components and SO 3 H, COOH and phenolic OH groups, and it showed a good catalytic activity for the dehydration of fructose into 5-hydroxymethylfurfural (HMF). By optimizing the reaction conditions, a high HMF yield of 81.1% with 100% fructose conversion was achieved in the presence of dimethylsulfoxide (DMSO) at 130 °C for 40 min. More importantly, the magnetic lignin-derived carbonaceous catalyst could be easily separated from the reaction mixture by using an external magnet, and when it was reused 5 successive runs, no obvious decrease in the yield of HMF was observed, indicating that the magnetic lignin-derived carbonaceous catalyst also exhibited an excellent catalytic stability.