Selective cleavage of C–O bond in lignin and lignin model compounds over iron/nitrogen co-doped carbon supported Ni catalyst

[Display omitted] •The Ni@Fe/NC shows good activity and selectivity for cleaving C-O bond in lignin.•NiFe alloy is formed in the catalyst which plays a crucial role in hydrogenolysis.•Aromatics especially guaiacols are dominant products from hydrogenolysis of lignin.•Possible reaction pathways based on hydrogenolysis of BPE and lignin were proposed. The utilization of lignin to produce high value-added chemicals is conducive to alleviating the fossil energy crisis. Herein, Ni nanoparticles supported on iron/nitrogen co-doped carbon was prepared by co-pyrolysis and solvothermal reduction method for catalytic hydrogenolysis (CH) of dealkaline lignin and its model compounds. The catalysts were prepared under different calcination temperature, N/C ratio and Ni loading, and the optimal catalyst was Ni10%@Fe/NC0.33–800 (calcination temperature: 800 °C, N/C ratio: 0.33, Ni loading: 10%) based the on the CH of benzyl phenyl ether (BPE). Ni10%@Fe/NC0.33–800 showed good catalytic performance on the selective cleavage of C-O bond of lignin and its model compounds. The BPE conversion reached up to 97.7% over Ni10%@Fe/NC0.33–800 under mild conditions (230 °C, 1 MPa H2, and 0.5 h) with toluene and cyclohexanol as major products. Catalyst characterizations suggest that N content affects the formation of NiFe alloy and the synergistic effect between Ni and Fe plays an important role in CH of BPE. Moreover, Ni10%@Fe/NC0.33–800 could promote the cleavage of C-O bonds in dealkaline lignin through CH and hence enhance producing aromatics such as phenols, aromatic ethers, and aromatic esters, among which phenols are the main aromatics with guaiacols predominant.