Graphene oxide mediated cellulose-derived carbon as a highly selective catalyst for the hydrolysis of cellulose to glucose

Abstract

A novel graphene oxide mediated flake carbon-based solid acid bearing SO3H, COOH, and OH groups was synthesized via hydrothermal carbonization of cellulose with a small amount of graphene oxide (GO) as a structure-directing agent and subsequent sulfonation. A series of characterization results show that with a certain addition of GO, the carbonized samples can transform from micron carbon spheres into crumpling layers, and the hydrophilcity of the GO induced catalysts also get increased. The prepared solid acid with 10wt% addition of GO (10-SGOC) exhibits excellent glucose selectivity (94.22%) at a moderate temperature (160°C). The catalytic performance of 10-SGOC is attributed to its lamellar structure with good hydrophilcity and the existence of functional OH, COOH and SO3H groups. The unique structure and hydrophilcity could improve the dispersion of the catalyst and provide effective interaction between reactants and functional groups on the solid acid, then OH groups adsorb cellulose on surface of the catalyst and acidic sites hydrolyze cellulose to glucose. Moreover, the catalyst displays good stability in catalytic activity; the selectivity of glucose could remain above 92.48% after four cycling experiments.