The utilization of lignin remains a great challenge due to its complex non-repetitive structure and the lack of efficient catalyst. Herein, a single-atom catalyst Ni@N-C was designed via a facile chelation-anchored strategy. Ni atoms were immobilized on the N-doped carbon carrier by a two-stage pyrolysis of a mixture of D-glucosamine hydrochloride, nickel acetate and melamine. D-glucosamine hydrochloride as a chelating agent prevented the aggregation of Ni2+, and melamine provided enough N to anchor Ni by forming Ni-N4 structure. Ni@N-C gave a 31.2% yield of aromatic compounds from lignin hydrogenolysis, which was twice higher than that achieved by Ni cluster catalyst. Based on the experimental and DFT calculation results, the higher activity of Ni@N-C was attributed to its lower H2 dissociation energy and the reduced energy barriers of the transition states. The strategy described opens an efficient green avenue for preparing single-atom catalyst that possesses outstanding activity in lignin depolymerization.

Exploring highly active and stable electrocatalyst for oxygen evolution reaction is important for the development of water splitting and rechargeable metal-air batteries. Herein, a hybrid electrocatalyst of CoFe alloy and CoxN heterojunction encapsulated and embedded in N-doped carbon support (CoFe-CoxN@NC) was in situ coupling via a pyrolysis process of a novel coordination polymer from lignin biomacromolecule. CoFe-CoxN@NC exhibited an excellent OER activity with a low overpotential of 270 mV at 10 mA•cm−2 and stability with increment of 20 mV, comparable to commercial Ir/C. DFT calculations revealed that CoxN and N-doped grapheme encapsulation can reduce the binding strength between *O and CoFe alloy, prevent metals leaching and agglomeration, and improve electron transfer efficiency, thereby, remarkably enhancing the OER activity and stability. In situ coupling strategy of alloy and nitride heterojunction on N-doped lignin-derived carbon provided a promising and universal catalyst design for the development of renewable energy conversion technologies.