Nitrogen-doped carbon: A metal-free catalyst for selective oxidation of crude 5-hydroxymethylfurfural obtained from high fructose corn syrup (HFCS-90) to 2,5-furandicarboxylic acid (FDCA)

In recent years, development of inexpensive and environmentally benign processes for catalytic conversion of lignocellulose biomass or biomass-derived carbohydrates into platform chemicals has gained increasing attention while also facing technological challenges related to the higher production costs. Here, we synthesized an inexpensive nitrogen-doped carbon (NC) materials by carbonization of bamboo sawdust mixed with melamine and K₂CO_3. The as-prepared NC materials were used first-time as catalysts for the selective oxidation of crude 5-HMF obtained from HFCS-90 into FDCA. Based on the obtained catalyst characterization and activity results, the rate of formation of FDCA is mainly dependent on the carbonization temperature of the catalyst, the quantity of graphitic N, and its related lattice defects in the carbon matrix. Under the optimized reaction conditions (NC-700 catalyst, 160 °C, 6 h, and 2 MPa O₂), the reaction obtained 100% HMF conversion and 83% FDCA yield using crude 5-HMF (88% purity). © 2020 Elsevier B.V.