Hydrolysis of cellulose in ionic liquids catalyzed by a magnetically-recoverable solid acid catalyst

• Catalytic hydrolysis of cellulose was studied in ionic liquid.
• Fe3O4@SiO2–SO3H showed high catalytic activity for the hydrolysis of cellulose.
• RS was obtained in a high yield of 73.2% under the optimal hydrolysis conditions.
• This catalytic system could be reused for several times without losing activity.

Catalytic hydrolysis of cellulose into reducing sugar (RS) over solid acid catalysts is one of efficient pathways for the conversion of biomass into fuels and chemicals. In this study, we developed a new method for the hydrolysis of cellulose into RS in ionic liquids catalyzed by a core–shell Fe3O4@SiO2–SO3H acid catalyst, which was prepared by the immobilization of sulfonic acid groups on the surface of silica-encapsulated Fe3O4 nanoparticles. The effect of various reaction parameters, such as reaction temperature, catalyst loading and the amount of water used, were studied. The Fe3O4@SiO2–SO3H showed a good activity with RS yield of 73.2% under the moderate conditions of 130 °C after 8 h reaction. Importantly, the catalyst Fe3O4@SiO2–SO3H could be easily separated from reaction mixtures by a permanent magnet. In addition, the catalyst showed a high stability during the hydrolysis of cellulose and it could be reused for several times without the significant loss of its activity.