Lignin-derived carbon-confined Ni catalyst for selective hydrogenolysis of lignin toward aromatic-rich SAF precursors.

Lignin represents a promising renewable feedstock for producing oxygenated aromatic intermediates that can serve as potential precursors for subsequent SAF upgrading. However, non-noble metal catalysts often suffer from metal aggregation and active-site degradation during lignin depolymerization. Herein, a carbon-confined Ni catalyst (20Ni/LC) was developed via a molecular self-assembly-assisted hydrothermal carbonization strategy. The constructed Ni-N-C interfacial structure regulates the electronic properties of Ni sites and strengthens metal-carbon interactions. Using enzymatic hydrolysis lignin as the feedstock, 20Ni/LC achieved a monophenol yield of 16.8 wt%, with guaiacol- and syringol-type compounds as the dominant products, and maintained stable performance over five consecutive cycles. Characterization results reveal that carbon confinement suppresses Ni nanoparticle migration and aggregation, while the Ni-N-C interface promotes the activation of lignin-derived oxygenated intermediates. This work provides an effective strategy for designing stable Ni-based catalysts with enhanced activity and durability for lignin valorization.