Bimetallic NiCo catalyzed enzymatic hydrolysis lignin hydrogenolysis to produce aromatic monomers

•Non-noble bimetallic NiCo catalyst was proposed to conduct lignin hydrogenolysis.•20.8 wt% yield of monomer products and 94.6% lignin liquefaction were obtained.•The catalytic performance of NiCo/C was much better than those of Ni/C and Co/C.•Synergetic effect between Ni and Co species promoted the catalytic activity.•NiCo/C had a superior hydrogen transformation ability and hydrogenolysis activity. Bimetallic catalyst gets increasing attention for the lignin valorization due to its outstanding catalytic activity. Herein, the non-noble bimetallic catalyst NiCo/C was proposed to conduct the hydrogenolysis of enzymatic hydrolysis lignin. 20.8 wt% yield of monomer products and 94.6% lignin liquefaction degree were obtained at the temperature of 260 °C, which was superior to the catalytic performances of Ni/C and Co/C catalysts. A series of catalyst characterizations were conducted to reveal the mechanism of bimetallic catalysis, including BET, XRD, SEM, TEM, XPS and H2-TPD methods. Results showed that the synergistic effect between Ni and Co species was the main reason for its high catalytic activity, which resulted in a superior hydrogen transformation ability and hydrogenolysis activity. GC–MS, GPC, elemental analysis and FT-IR measurements were also used to investigate the hydrogenolysis products and the results also confirmed the superiority of bimetallic NiCo catalyst resulted from synergistic effect of Ni and Co.