Selective Deoxygenation of Lignin-Derived Phenols and Dimeric Ethers with Protic Ionic Liquids

Hydrodeoxygenation (HDO) of lignin-derived phenols and dimeric ethers to bio-fuels has great significance for advanced utilization of renewable lignocelluloses and the future bio-based economy. Herein, we find that the deoxygenation process during lignin-derived model compounds HDO process could efficiently catalyzed by low-cost protic ionic liquids under mild conditions. 2-hydroxy-N-(2-hydroxyethyl)-N-methylethanaminium trifluoromethanesulfonate ([BHEM]CF3SO3) shows the highest catalytic activity for deoxygenation reaction during lignin derived compounds HDO process with Rh/C as the hydrogenation catalyst. The conversion of phenol is 100% under 4 MPa H2 at 130 oC for 6 h, the yield of cyclohexane is 93.3%. Furthermore, the catalytic system with [BHEM]CF3SO3 as the deoxygenation catalyst and Rh/C as the hydrogenation catalyst, demonstrates efficient catalytic activity for various lignin-derived phenols and dimeric ethers with ≥99.0% conversion and >90.0% selectivity. The catalytic system is reused five ti...