In this work, hydroxyl-enriched glucose-based carbonaceous sphere (HEGCS) is prepared by hydrothermal method as an accelerator to enhance the hydrolytic efficiency of the treated cellulose to sugar in low-acidic aqueous system under microwave radiation. Due to the strong affinity of HEGCS to cellulose, during the hydrolysis, the treated cellulose can be flaked into small fragments by HEGCS, which is like a "microball milling", and accordingly, the hydrolytic accessibility of cellulose is extremely improved. Highly efficient hydrolysis of cellulose to sugar is finally achieved in HEGCS containing 0.02 mol/L sulfuric acid. One hundred percent conversion of cellulose and 96.0 ± 4.0% total reducing sugar (TRS) yield was obtained within 15 min under microwave radiation. The average content of glucose in sugar products is over 70%. Our research not only obtains a catalytic accelerator to establish an effective method for hydrolyzing treated cellulose to sugar but also provides the idea for regulating cellulose accessibility during hydrolysis to achieve high efficiency in the hydrolysis of cellulose.
Keywords: carbonaceous sphere; catalytic accelerator; cellulose; hydrolysis; microwave radiation.