Synergistic Co-Zn dual atomic sites drive C-lignin hydrogenolysis via vicinal C-O cleavage

C-lignin, a natural biopolymer of caffeyl alcohol subunits linked by benzodioxane motifs, is an ideal feedstock for direct catechol production. However, its hydrogenolysis is hindered by the high bond dissociation energies and steric congestion of vicinal C-O bonds in benzodioxane structures. Here, we report a low-loaded Co-Zn dual single-atom catalyst (Co_SA-Zn_SA@NC) that enables efficient C-lignin hydrogenolysis, achieving 84.6% catechol yield, 82% selectivity toward 4-propylcatechol, and a turnover number five times higher than precious Ru/C, attributing to the synergistic effect of the dual atomic sites. The major product, 4-propylcatechol, can be readily purified and upgraded into diverse value-added molecules. Mechanistic investigations reveal that the Zn and Co species, acting as the directing and active centers, respectively, synergistically drive the quasi-concerted cleavage of the vicinal C-O bonds. This work presents an atomically dispersed non-precious metal catalyst for C-lignin hydrogenolysis, providing a sustainable route to well-defined aromatics.