Efficient Glucose Hydrogenation to Sorbitol by Graphene-like Carbon-Encapsulated Ru Catalyst Synthesized by Evaporation-Induced Self-Assembly and Chemical Activation

As one of the important value-added chemicals that has wide applications, the catalytic hydrogenation of glucose to sorbitol has been a hot topic in biomass upgrading. In order to support the prosperity of the sorbitol industry, catalysts with superior activity, higher selectivity, longer life, and lower cost are desirable. Herein, tremelliform graphene-like carbon-encapsulated Ru catalysts (Ru/GLC) were synthesized from 4-nitrocatechol by using solvent evaporation-induced self-assembly and KHCO3 chemical activation processes. The Ru/GLC materials were used for the catalytic hydrogenation of glucose to sorbitol, and the best Ru/GLC-600 sample prepared at a 600 °C activation temperature exhibited both high glucose conversion of 100% and sorbitol yield of 96.8% at 140 °C and 3 MPa H2 in 120 min. The Ru/GLC-600 catalyst exhibited excellent stability and durability that sorbitol yield could be remained at 95.4% after recycling five runs. The catalyst was applicable to concentrated glucose solutions (50 wt %) with 95.6% sorbitol yield. Compared with previously reported catalysts, Ru/GLC catalyst had lower apparent activation energy (Ea = 30.66 kJ/mol) and higher turnover frequency (TOF = 1680.6 h–1). This work provides a simple one-pot synthesis strategy for graphene-like carbon materials for metal encapsulating, and the prepared materials exhibited high catalytic activity and stability for glucose hydrogenation to sorbitol.