RuNi nanoparticles embedded in N-doped carbon nanofibers as a bimetallic catalyst for the hydrogenolysis of peanut shell lignin

Peanut shell, as a widespread agricultural waste, is a biomass resource rich in lignin that has not been fully utilized. Herein, a novel and efficient hydrogenolysis process was provided for the selective decomposition of peanut shell lignin. Ru and Ni nanoparticles embedded within N-doped nanofibers were synthesized by a simple electrospinning technique and carbonized to obtain a bimetallic catalyst (RuxNiy-NCNFs). With the optimized catalyst of Ru2Ni1-NCNFs, 74.46 wt% of lignin oil was obtained with a char formation rate lower than 2.44 wt% at 300 °C for 3 h without an external hydrogen source. 2D-HSQC-NMR demonstrated that representative interunit linkages, such as β-O-4, β-5, and β-β, were considerably degraded during the depolymerization process. The obtained lignin oil has a narrow molecular weight distribution, low molecular weight and high burning value, indicating that it has great potential to become a high-quality aromatic fuel through subsequent upgrade processing. This study opens a novel avenue toward the exploration of highly efficient but low-cost bimetallic catalysts for lignin hydrogenolysis.