Enhancing aromatic hydrocarbon formation via catalytic depolymerization of lignin waste over Ru/WOx/N-C catalyst

Abstract

Direct converting Kraft lignin into valuable chemicals by catalytic hydrogenolysis is a promising method to develop biomass valorization. In our research, the multifunctional porous carbon material catalyst was prepared for lignin depolymerization reaction. Through the introduction of ammonium oxalate as both foaming agent and nitrogen source increased the carbon materials surface area (608.74 m2/g), which improved the stability and dispersion of Ru and WOx nanoparticles. Based on the catalyst characterization and liquid product composition analysis, the lignin could quickly achieve hydrodeoxygenation process over the connected multi-stage pore structure assisted with Ru metal center and WOx oxophilic sites. Especially, the 96.89 wt% bio-oil yield, 36.85 wt% monomer yield and 20.85 wt% arenes yield were achieved over a porous 5Ru/30WOx/N-C catalyst. Under the optimal reaction condition, the higher heating values of bio-oil could increase to 35.68 MJ/kg. This research provided a new method for catalyst design towards highly efficient and selective hydrogenolysis of lignin to useful aromatic chemicals.