CO 2 reduction on single-atom Ir catalysts with chemical functionalization.

As promising catalytic systems, single-atom catalysts (SACs) demonstrate improved catalytic performance for electrochemical reactions. However, the pinning of metal atoms on surfaces usually depends on the adsorption on defects. In this study, defect-free functionalization by attaching IrX3 (X = F or Cl) complexes on the MoS2 monolayer is theoretically demonstrated. The ligand-based method offers a damage-free route for stabilizing SACs on 2D materials. We demonstrate the CO2 reduction process on MoS2 -IrX3 with a small change in free energy and a low onset potential. The d6 shell of Ir acts as a molecular joint with universal orbital orientations, which benefits the adsorption of different reaction intermediates. This study shows the superiority of defect-free functionalization of 2D materials using SAC-ligand complexes.