A sulfonated carbon material was prepared by incomplete hydrothermal carbonization of glucose followed by sulfonation. The carbon material contained -SO3H, -COOH, and phenolic -OH groups, and exhibited high catalytic performance for the hydrolysis of cellulose. A total reducing sugar (TRS) yield of 72.7% was obtained in ionic liquid 1-butyl-3-methyl imidazolium chloride at 110 degrees C in 240 min reaction time. The effect of water on the hydrolysis of cellulose in the catalytic system was studied. A water content of less than 2% in the ionic liquid promoted the formation of TRS, whereas a water content of greater than 2% lead to a decrease in TRS. The sulfonated carbon material catalyst was demonstrated robe stable for five cycles with minimal loss in catalytic activity. The use of an ionic liquid with functionalized carbon catalyst derived from glucose provides a green and efficient process for cellulose conversion. (C) 2012 Elsevier Ltd. All rights reserved.