Reaction synergy of RuFe bimetallic catalysts on mordenite in lignin hydrogenolysis for aromatic compounds production

Abstract

Exploring the value-added utilization of lignin showed the great significant to realize the efficient conversion of lignocellulosic biomass, which had good environmental, economic, and social benefits. However, the catalytic hydrogenolysis of lignin faced the great problems, including harsh reaction conditions and low product yield. In this research, the FeOx modified Ru/mordenite (M) was synthesized by deposition–precipitation method and strengthened the effective lignin conversion process. Ru_2.5%Fe_2.5%/M showed the high catalytic hydrogenolysis activity of β-O-4 and α-O-4 bond under the condition of 260 °C, 1 MPa H₂, and 3 h in the methanol. Though the research about reaction of model compounds and several characterizations, synergistic action of highly dispersion RuFe nanoparticles and acidic sites significantly promoted the breakage of C-O bond. The introduction of Fe species can reduced the size of metal nanoparticles. The lignin oil reached the high value of 47.8 wt%, and contained the low RC value of phenolic compounds. Finally, the reaction mechanism of lignin catalytic hydrogenolysis was discussed, and it found that the highly dispersed RuFe nanoparticles enhanced the synergistic transfer ability of H₂ and methanol to release H•. This research would give some useful understandings for the efficient thermochemical conversion of lignin.