Sustainable utilization of lignocellulose: Preparation of furan derivatives from carbohydrate biomass by bifunctional lignosulfonate-based catalysts

Bifunctional lignosulfonate-based catalysts (LS-M) with Lewis acid and basic sites were designed and prepared by immobilizing metal ions on lignosulfonate. Catalysts were characterized by XRD, XPS, SEM, EDX, TEM, TGA, NH 3 /CO 2 -TPD and FTIR, and applied in transformation of carbohydrate biomass to furan derivatives (HMF/furfural) in mixed water/THF systems. With LS-Cr as catalyst, the optimized yields of HMF from cellulose, glucose and mannose were 46.3%, 60.4% and 68.8%, and that of furfural from xylan, xylose and arabinose were 40.2%, 73.1% and 51.6%, respectively. The catalysts could be easily recycled with negligible wastage of the active metal ions.