Enhanced Production of 5‐Hydroxymethylfurfural from Cellulose via Synergistic Catalysis of Solid Acid and Molten Salt Hydrates Solvent

Producing 5‐hydroxymethylfurfural (5‐HMF) from abundant and renewable cellulose is a practical method for lignocellulosic biomass valorization. Nonetheless, the high crystallinity of cellulose restricts the accessibility of catalysts, and the complex reaction pathway generally results in the formation of intermediate by‐products and 5‐HMF degradation. Molten salt hydrates (MSHs) are unique in dissolving crystalline cellulose and their weak Brønsted acidity can facilitate cellulose hydrolysis to glucose. In this work, one‐pot conversion of cellulose into 5‐HMF was carried out in LiBr MSHs/acetone biphasic system. The solid acid, Sn‐β, was used in the conversion to compensate for the shortages of MSH Lewis acidity. Under the optimized reaction condition at 180 °C for 20 min, a high 5‐HMF yield of 66.88% was obtained from cellulose conversion. The influences of reaction conditions on 5‐HMF production were studied, and the synergistic effects of solvents and solid acid were established. The catalyzed can be readily recycled and regenerated via calcination. This technique provides a theoretical foundation and technical basis for constructing a one‐step conversion of commercial cellulose to value‐added 5‐HMF, which proposes significant effects on lignocellulose valorization.