Bifunctional ruthenium and molybdenum oxide nanoparticles supported on activated carbon were designed and empolyed in hydrodeoxygenation (HDO) of lignin-derived aromatics for lignin depolymerization products upgrading. The typical model phenolic monomers and dimers could be efficiently converted to hydrocarbons over RuMoOx/C under mild conditions in decalin, i.e. at 160℃ and 30 bar H2. When HDO reaction was executed with real lignin-derived aromatics at 280℃and 30 bar H2, the total yield of hydrocarbons and cyclohexanol/ether were 56.93% and 18.99%. The main hydrocarbons were cyclohexane and alkyl-substituted cyclohexane. Characterization results revealed that the nanoparticles of ruthenium and molybdenum oxide species highly dispersed on activated carbon, while the presence of Ru active site and MoOx on activated carbon were crucial for the remarkable hydrogenolysis/ hydrodenation and deoxygenation activity, respectively. The hydrodeoxygenation pathway of diphenyl ether as a model compound catalyzed by optimized RuMoOx/C was discussed and the structure-activity relationship in hydrodeoxygenation was proposed.
Keywords hydrodeoxygenation, lignin model compound, model dimer, Lignin-derived aromatics, RuMoxO/C catalyst