Catalytic Conversion of Lignin Model Compound and Kraft Lignin over Reduced Ru/C Catalyst

Catalytic conversion of lignin into valuable liquid products has been a promising approach. Herein, we reported the catalytic conversion of the lignin model compound and Kraft lignin over reduced Ru/C catalyst with different industrial organic solvents using a high‐pressure/ high‐temperature reactor in a nitrogen atmosphere. The results showed reduced Ru/C catalyst is stable for two runs and active for the conversion of the lignin model compound (2‐phenoxy‐1‐phenyl ethanol) with a breaking of the C−O ether bond at high temperature. In the case of Kraft lignin, 2‐butanol and ethanol were potential solvents for the lignin conversion. The Ru/C catalyst enhanced the conversion of lignin, and the highest Kraft lignin conversion (~68 %) was obtained by using ethanol solvent at 220 °C for 1 h reaction. The product distribution with most small phenolic compounds demonstrated the potential of Kraft lignin conversion over the Ru/C catalyst. Kraft lignin was converted into phenolic compounds over reduced Ru/C catalyst using organic solvents such as methanol, ethanol, and 2‐butanol. Ethanol and 2‐butanol are potential solvents with high solubility/conversion of Kraft lignin. In addition, the reaction temperature has a strong impact on the conversion of the model lignin compound, 2‐phenoxy‐1‐phenyl ethanol, and the cleavage of the C−O ether bond was obtained at high temperatures.