(583ck) Novel Polymeric Solid Acid Catalysts for Biomass Hydrolysis
Dual functional polymeric solid acid catalysts are synthesized to facilitate cellulose dissolution and catalyze its hydrolysis reaction. A poly (styrene sulfonic acid) (PSSA) polymer chain is immobilized on surfaces of glass or ceramic membrane substrates and used to catalyze biomass hydrolysis. A neighboring poly (vinyl imidazolium chloride) ionic liquid (PIL) polymer chain is grafted from the surface to help solubilize lignocellulosic biomass and enhance the catalytic activity. The acidic polymeric PSSA chain was synthesized via surface initiated atom-transfer radical polymerization (ATRP) whereas the adjacent PIL chain was synthesized via UV-initiated radical polymerization. The two chains were grafted from randomly immobilized UV and ATRP initiators on the substrate surface. It is possible to tune independently the relative ratio as well as the chain length, chain density of the two polymeric nanostructures to optimize the catalytic activity for cellulose hydrolysis reaction. Our synthesized solid acid catalysts demonstrate over 97% and 32% TRS yields from crystalline α-cellulose hydrolysis in ionic liquid [EMIM]Cl and aqueous solutions respectively. These catalysts are stable and maintain high catalytic activity after repeated runs.