Efficient lignin hydrogenolysis over N-doped macroporous carbon supported Ru catalyst

To cope with the challenge of insufficient interaction between lignin macromolecules and catalytic active sites in heterocatalysis systems which hindered the efficient hydrogenolysis of lignin, a lignin-derived N-doped macroporous carbon supported Ru catalyst (Ru/LNPC) was prepared via the pyrolysis of alkali lignin with potassium hydroxide as the activator and ammonium oxalate as the pore forming agent. The LNPC carrier featured a hierarchical porous structure with the diameter of macropores ranging from 50 nm to 10 μm, enhancing the adequately contact between the lignin macromolecules and Ru NPs. The doping nitrogen in the carbon carrier led to well dispersed Ru nanoparticles with average size of 1.08 nm, providing abundant active metallic centers. Therefore, Ru/LNPC exhibited excellent catalytic activity and stability to hydrogenolysis of lignin. Under the condition of 1.0 MPa H 2 at 280 ºC for 2 h, Ru/LNPC contributed to the yield of 45.6 % aromatic monomers from the depolymerization of lignin. After five recycling, Ru/LNPC still showed significant activity. This work provided a new strategy for designing catalysts for efficient hydrogenolysis of lignin and further facilitating its high-value utilization.