Selective hydrolysis of cellulose and polysaccharides into sugars by catalytic hydrothermal method using sulfonated activated-carbon

Abstract

Mildly hydrothermal reaction using solid acid catalysts for cellulose hydrolysis into glucose has potential abilities to be one of the key technologies for a future sustainable society using cellulose biomass. Among the solid acid catalysts tested, such as H-form zeolite catalysts and sulfated and sulfonated catalysts, sulfonated activatedcarbon (AC-SO 3H) catalyst showed remarkably high yield of glucose in the hydrolysis of cellulose with β-1,4- glycosidic bonds under hydrothermal conditions at temperatures around 423 K. The AC-SO 3H catalyst with hydrothermal pre-treatment had excellent catalytic properties attributed to the high hydrothermal stability and the strong acid sites of the sulfo functional groups and the activated carbon surfaces for polysaccharide adsorption. A bifunctional sulfonated activated-carbon supported platinum (Pt/AC-SO 3H) was prepared by impregnation of platinum on activated carbon (AC) and sulfonation of the prepared Pt/AC. Gluconic acid was produced from polysaccharides, such as starch and cellobiose, in water at 393 K under air by a one-pot process using the Pt/AC- SO 3H catalyst.