Conversion of biomass-derived carbohydrates into 5-hydroxymethylfurfural catalyzed by sulfonic acid-functionalized carbon material with high strong-acid density in γ-valerolactone

A carbonaceous solid acid catalyst with high strong-acid density was synthesized by facile functionalization of a biomass-derived mesoporous carbon with benzenesulfonic acid. The catalyst was characterized by using Fourier transform infrared spectroscopy, elemental analysis, X-ray photoelectron spectroscopy, transmission electron microscopy, and N2 adsorption–desorption. The carbonaceous solid catalyst containing Brønsted acid sites was used for the production of 5-hydroxymethylfurfural (HMF) from hexoses such as fructose, glucose, and cellulose in γ-valerolactone (GVL)-H2O mixture. By reaction at 130 °C for 20 min using fructose as a feedstock, an HMF yield 78.1% was achieved. The catalytic performance of the catalyst in conversion of fructose into HMF hardly changed over seven cycles, demonstrating that the catalyst had excellent recyclability. The yields of HMF derived from glucose and cellulose reached 33.2 and 22.5%, respectively, whereas those of total furans were 42.1 and 33.7%, respectively. The proposed reaction system was promising in transforming biomass-based carbohydrates into fine chemicals, given the use of green functionalization methods, the utilization of sustainable biomass-derived carbon precursor and solvents, catalyst with high acid density, and the availability of high HMF yield.