A bifunctional recoverable catalyst based on phosphotungstic acid for cellulose hydrolysis to fermentable sugars

Chemocatalytic production of platform compounds from cellulose is remarkable for both clean energy development and environmental pollution control. A battery of bifunctional recyclable amino acid functionalized phosphotungstic acid nanosilver (AAPTA-Ag) catalysts were synthesized for hydrolyzes cellulose in ionic liquid ([BMIM]Cl). The “catalytic domain” and “binding domain” derived from the Brønsted acidity and functional groups (hydroxyl, carboxyl) in the catalyst can synergistically promote the hydrolysis of cellulose effectively. What's more, the tyrosine-derived TyrPTA-Ag with abundant functional groups achieved a significant total reducing sugar (TRS) yield and cellulose conversion of 71.9% and 100% respectively at 140 °C for 1.5 h. Meanwhile, the catalyst cycled to the fifth time still showed good catalytic performance. In light of this research, it is possible to convert cellulosic biomass to TRS in a milder case, giving a relatively higher product yield in [BMIM]Cl solution.