Constructing Single-atom Ni on N-doped Carbon Via Chelation-anchored
Strategy for the Hydrogenolysis of Lignin
Abstract
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.