(289a) Homogenous Hydrolysis of Cellulose Catalyzed By Solid Acid in Inorganic Ionic Liquid

Zeolites (ZSM-5 and Beta) with different SiO₂/Al₂O₃ molar ratios were synthesized for cellulose hydrolysis in an inorganic ionic liquid system (lithium bromide trihydrate solution, LBTH) under mild conditions. The results indicated that 2% zeolite could completely hydrolyze cellulose at 140 °C within 3 h with a single-pass glucose yield 61%. It was found that the texture properties of zeolite had little effect on catalytic activity, while acidity of zeolite was crucial to the cellulose hydrolysis. Pyridine-Fourier Transform Infrared (Py-FTIR) study and acidity measurement demonstrated that H⁺released from the acid sites of zeolite via ion-exchange with Li⁺ in the LBTH was the key active species which catalyzed the cellulose hydrolysis. Dissolved cellulose and the free H⁺ in the LBTH system ensured the homogeneous hydrolysis of cellulose, which were the primary reasons for the excellent performance of zeolite-catalyzed cellulose hydrolysis in the LBTH. The zeolite could be recovered, regenerated, and reused with stable catalytic activity.