LAUSR

Ethanol is an important bulk chemical with diversified applications. Biomass derived ethanol is traditionally produced by fermentation. Direct cellulose conversion to ethanol by chemo-catalysis is particularly promising but remains a big challenging. We report a one-pot hydrogenolysis of cellulose into ethanol using graphene layers encapsulated nickel (Ni@C) catalysts with the aid of phosphoric acid (H3PO4) in water. The cellulose is hydrolyzed into glucose which is activated by forming cyclic di-ester bonds between the OH groups of H3PO4 and glucose, promoting ethanol formation under the synergistic hydrogenation of Ni@C. A 69.1% of ethanol yield (carbon mole basis) was obtained, which is comparable to the theoretical value by glucose fermentation. Ethanol concentration of up to 8.9 wt% was obtained at the increased cellulose concentration. This work demonstrates a chemo-catalytic approach for high yield and high concentration of ethanol production from renewable cellulosic biomass.