Geometric and Electronic Effects in the Binding Affinity of Imidazole-Based N-Heterocyclic Carbenes to Cu(100)- and Ag(100)-Based Pd and Pt Single-Atom Alloy Surfaces

Abstract

We have conducted nonlocal periodic density functional theory (DFT) calculations of N-heterocyclic carbenes (NHCs) adsorbed to Pd/Cu(100), Pt/Cu(100), Pd/Ag(100), and Pt/Ag(100) single atom alloys (SAAs) utilizing the nonlocal optPBE-vdW functional. NHCs with electron donating groups (EDGs) are predicted to bind more strongly to the SAA surface compared to NHCs functionalized with electron withdrawing groups (EWGs). Our calculations show that NHCs typically bind to SAA geometries containing a small space between the heteroatom sites for the SAAs considered. Generally, this pattern is predicted to persist for a single NHCs or for a pair of NHCs bound to the SAA surfaces. Approximate linear relationships between NMR-based parameters and NHC-SAA binding energies are uncovered. We predict that the binding of NHCs to SAA surfaces is composition-dependent and heteroatom geometry dependent.

The Electron-Rich and Nucleophilic N-Heterocyclic Imines on Metal Surfaces: Binding Modes and Interfacial Charge Transfer

“…Employing the Vienna Ab Initio Simulation Package (VASP), periodic density functional theory calculations were conducted to investigate the binding of molecules on Cu(111) and Ag(111) surfaces. In all calculations, the optPBE-vdw functional together with projected augmented wave (PAW) pseudopotentials together with a plane-wave cutoff for the wave functions was 400 eV .…”