Efficient hydrolysis of cellulose to reducing sugars over peanut shell-derived carbon-based solid acid with a large surface area

A carbon-based solid acid with a large surface area (CSALA; SBET = 237.9 m2/g) was prepared from peanut shells. Compared with a CSA with a small specific surface area (SBET = 5.6 m2/g), the CSALA enabled greater cellulose hydrolysis. Under optimized conditions, the yield of reducing sugars over 2.5 h at 110 & DEG;C was 60.5% using the CSALA. When a CSA was used, the yield of reducing sugar only reached 58.6% after 4 h at the same temperature. The results showed that the CSALA had higher activity because of its larger specific surface area and more numerous surface acid centers. However, it was unstable and was deactivated after one use. The loss of some of the sulfonic groups on the CSALA surface, and the conversion of some of those groups to sulfate groups under the action of 1-butyl-3-methylimidazolium chloride ionic liquid were the main reasons for the deactivation of the CSALA. In addition, most of the residual sulfonic groups were located in the micropores of CSALA and could not participate in the cellulose hydrolysis reaction.