Construction of single-site catalysts by synergism of micropore trapping and nitrogen anchoring: A theoretical insight

Single-site catalysts (SSCs) have aroused broad interests due to their maximized atomic efficiency and unique catalytic properties. The facile and controllable preparation of SSCs is always a challenging issue. Very recently, we reported the simplest construction of precious-metal single-site catalysts by the synergism of micropore trapping and nitrogen anchoring. Herein, we employed density functional theory modelling to systematically reveal the general mechanism behind this trapping strategy with the different sizes of micropores and metal complex anions. The results demonstrate that the carbon micropores can well trap the metal complex anions with the similar size and shape, since the micropore trapping effect comes from the synergism of the van der Waals force relating to the number of involved atoms and the electrostatic interaction from N dopants. The captured complex anions gradually get reduced at the micropores, and the final coordination is related to the reduction condition and the ligands of the complex anions. The deep theoretical insight into this strategy provides a new route to design the advanced SSCs by tuning the size and shape of carbon micropores to match the targeted metal complex anions, and regulating the ligands and reduction conditions to control the coordination environment.