Synergistic effect of active metal-acid sites on hydrodeoxygenation of lignin-derived phenolic compounds under mild conditions using Ru/C-HPW catalyst

Hydrodeoxygenation (HDO) is an indispensable reaction in the field of fuel and chemical production, and the synergistic effect of metal-acid sites in the catalyst makes great influence to it. Herein, a bifunctional catalyst of Ru/C combined with phosphotungstic acid (HPW) was employed for the hydrodeoxygenation (HDO) of lignin derived compounds to make full use of the synergistic effect of active metal-acid sites. HPW possessed a temperature-controlled phase-transfer behavior, which made it dispersed well on the surface of Ru/C catalyst and resulted in a close integration of acid site with metal site. Ru/C-HPW catalyst also owned the advantage of high reaction rate and good recyclability, which exhibited no obvious catalytic activity loss after 5 runs. Lignin derived phenolic compounds including monomers and dimers enabled to obtain an efficient transformation to cycloalkanes at the temperature of 200 ?. Moreover, a high HDO reaction efficiency of raw lignin-oil was also observed in this study, with the increasing hydrocarbon content from 5.5% to 78.9%. This novel catalytic system can achieve a high HDO efficiency under mild conditions.