DFT study of electronic and structural properties of Agn (n=2-10) nano clusters and their interaction with carbon monoxide

The electronic and structural properties of Agn (n=2-10) nano clusters and their interaction with carbon monoxide have been investigated using DFT. The average equilibrium Ag-Ag distance and binding energy per atom of clusters increase with cluster size and close to the experimental values of bulk material. The smallest HOMO-LUMO energy gap (ΔEH-L) is related to the Ag3 cluster indicating more reactivity of this cluster compared to the other clusters. The most stable adsorption modes of CO are adsorption from carbon end to the one atom of the cluster. The maximum CO adsorption energy was observed for the Ag3 cluster because of the more reactivity of this cluster. The NBO calculations revealed that for CO adsorption, charge density has been transferred from s and p orbitals of the oxygen atom to the p orbital of sliver atom of the cluster. The Wiberg bond indexes were also calculated according to the NBO calculations