DFT/CC investigation of physical adsorption on a graphite (0001) surface

Abstract

The physical adsorption of molecules (C₂H₂, C₂H₄, C₂H₆, C₆H₆, CH₄, H₂, H₂O, N₂, NH₃, CO, CO₂, Ar) on a graphite substrate has been investigated at the DFT/CC level of theory. The calculated DFT/CC interaction energies were compared with the available experimental data at the zero coverage limit. The differences between the DFT/CC results and experiment are within a few tenths of kJ mol⁻¹ for the most accurate experimental estimates (Ar, H₂, N₂, CH₄) and within 1–2 kJ mol⁻¹ for the other systems (C₂H₂, C₂H₄, C₂H₆, C₆H₆, CO, CO₂). For water–graphite and ammonia–graphite complexes, DFT/CC predicts interaction energies of 13 kJ mol⁻¹ in good accord with the DF-DFT-SAPT and DFT-D calculations. The relevance of the results obtained with the coronene model for the description of the physisorption on graphite surface was also studied.