Multilayer mesoporous carbon catalysts for the efficient synthesis of 5-hydroxymethylfurfural in glucose-derived natural deep eutectic solvent

In this work, different multilayer mesoporous carbon solid catalysts were prepared and applied for 5-hydroxymethylfurfural (HMF) synthesis in carbohydrate-derived natural deep eutectic solvents (NADES). The structure of the carbon carriers and solid acids were systematically detected by various characteristics such as BET, SEM, TEM, XRD, FT-IR, and TGA, and stated the formation processes of the soft-templating copolymers and the multilayer mesoporous carbons. The carbon solid acidic catalysts showed effective performance conversion of carbohydrates such as fructose and glucose, with high 5-hydroxymethylfurfural (HMF) yields of 91.3 % and 60.1 % obtained from the NADES, respectively. Based on the proposed catalytic mechanism, the critical energy barriers and rate-limiting steps in glucose isomerization were demonstrated using Density Functional Theory (DFT) method. Both the carbon-based catalyst and the NADES reaction system could be easily recycled. This work provided a novel method for carbon catalyst synthesis and suggested a practical pathway from carbohydrates to value-added chemicals.