Production of liquid fuels from Kraft lignin over bimetallic Ni–Mo supported on ZIF-derived porous carbon catalyst

Abstract

Non-noble bimetallic NiMo supported on zeolitic imidazolate framework-derived porous carbon (NiMo@FDC) catalyst for lignin depolymerization has been successfully developed. The synergism between Ni and Mo species in NiMo@FDC catalyst could promote the catalytic cleavage of C–O linkages in Kraft lignin. At a low reaction temperature of 240 °C and under 4 MPa H₂, the lignin liquefaction yield was 98.85 wt% and minimum coke yield was 1 wt%, particularly when using 10%NiMo@FDC catalyst. Additionally, at a high reaction temperature of 300 °C and under 2 MPa H₂, there was an overall yield of 86 wt% of liquid product and 42 wt% of petroleum ether soluble product. The higher heating value (HHV) increased from 27.65 MJ kg⁻¹ to 34.11 MJ kg⁻¹. In the cycling experiment, the bifunctional catalyst also demonstrated reversability and stability. The synergy of Ni hydrogenation sites and Mo coupled adsorption sites identified a possible mechanism path, which could offer considerable potential for lignin depolymerization.