A theoretical study of the ability of 2D monolayer Au (111) to activate gas molecules

The adsorption and activation of gas molecules are investigated substantially in solid-gas heterogeneous catalysis. Here we investigated the interaction between gas molecules and unique two-dimensional monolayer Au (111) structure using density functional theory. It is found that CO2, H2O, N2 and CH4 molecules are weakly adsorbed on the surface with the adsorption energies between −0.150 and −0.250 eV due to van der Waals interaction. While CO, NO, NO2, and NH3 molecules are adsorbed more stably with the adsorption energies between −0.300 and −0.470 eV. Especially, the bond length of CO is stretched by 0.038 A and the bond angle of NO2 is obviously enlarged by 10.460°. The activation originates from the rearrangement of molecule orbitals and the orbitals hybridization between the partial orbitals of gas molecules and Au-5d orbitals. The fundamental analyses of adsorption mechanism and electronic properties may provide guidance for the applications of two-dimensional monolayer metal catalysis. PACSnumbers 73.22.-f, 73.61.-r