Unsymmetrically N, S-coordinated single-atom cobalt with electron redistribution for catalytic hydrogenation of quinolines

Abstract

Engineering unsymmetrical coordination is an efficient strategy for improving the performance of carbon supported single-atom catalysts for diverse applications. However, the exploration of this strategy to prepare carbon supported single-atom catalysts for hydrogenation reaction is still in infancy, especially for hydrogenation of quinolines. Herein, we report a protein-metal-ion-network strategy for preparation of single-atom cobalt supported on hierarchically porous carbon (SA-Co/NSPC). SA-Co/NSPC features unsymmetrically N/S-coordinated metal center, i.e., Co1–N3S1. Moreover, the carbon matrices possess an ultra-thin two-dimensional morphology and hierarchically porous structures. SA-Co/NSPC catalyst with Co1–N3S1 active site exhibits excellent catalytic performance for hydrogenation of N-heterocycles. The DFT calculation results show that the site of Co1–N3S1 reveals a significant electron redistribution in comparison to the Co1–N4, leading to a lower H* diffusion barrier and quinoline hydrogenation reaction barrier. SA-Co/NSPC catalyst combined with the unique hierarchically porous structure and high active Co1–N3S1 owns extraordinary catalytic performance for hydrogenation of quinolines.