Temperature‐responsive Solid Acid Catalyst for Cellulose Hydrolysis to HMF

Abstract

Abstract Conversion of cellulose to the platform chemical, 5‐hydroxymethylfurfural (HMF), is of importance to the manufacture of a variety of bio‐chemicals and biofuels. However, low mass and heat transfer between a solid catalyst and the cellulose particles severely hampers the efficiency of cellulose conversion. In effort to conquer the obstacle, a series of N‐doped mesoporous carbon materials (MCNs) were prepared and employed to catalyze cellulose to HMF by use of the temperature‐responsive HCl‐releasing effect of MCNs. In this way, acid‐base dual catalytic environments can be constructed for efficient conversion of cellulose to HMF. MCN‐2‐DH⋅ n HCl is capable of adsorbing chemically 1.07 mmol HCl/g at room temperature and releasing about 1.01 mmol HCl/g when being heated to 220 °C. It is found that MCN‐2‐DH⋅ n HCl is an excellent catalyst for cellulose conversion, yielding 52.6% HMF, 27.6% reducing sugars and 4.1% levulinic acid with a cellulose conversion of 96.4% after reacting at 220 °C for 80 min. A total carbon yield of 84.3% can be achieved. Moreover, four times of recycling tests demonstrate that MCN‐2‐DH⋅ n HCl possesses good temperature‐responsive stability in aqueous solution.