Abstract: Dual Brønsted acidic ionic liquid 1-(propyl-3-sulfonate) imidazolium hydrogen sulfate[SO₃H-(CH₂)₃-HIM] [HSO₄] was supported onto the surface of Fe₃O₄@SiO₂ to prepare recyclable magnetic catalyst Fe₃O₄@SiO₂-IL by chemical modification. The magnetic catalyst was characterized by FT-IR, TEM and further utilized in the hydrolysis of cellulose. The influences of reaction temperature, reaction time, catalyst dosage and water content on the convertion of cellulose to reduction sugars were investigated. The FT-IR of Fe₃O₄@SiO₂-IL showed absorption peaks of —SO₃H and that of imidazole ring, which indicated that the ionic liquid was successfully loaded on Fe₃O₄@SiO₂. The TEM images showed that the particles size of Fe₃O₄ was about 250 nm and the surface of particles had no significant change after packing and modification of ionic liquid. With the dosage of 0.1 g cellulose, 2.0 g ionic liquid [Bmim]Cl, 0.2 g magnetic catalyst, 0.2 g water and reacting under 100 ℃ for 40 min, the yield of the total reducing sugars reached 52.5 %. After magnetic separation, the catalyst could be reused for 5 recycles without the loss of catalytic activity.

Key words: cellulose, magnetic loaded catalyst, hydrolysis, reducing sugar