First Principle Study: Absorption of Molecular Hydrogen Sulphide on Gold Clusters

Igunbor, Emmanuel (2009-11-13)


We present theoretical results of the study of H 2 S adsorption on gold cluster Au n (n = 1, 5) using density functional theory with Perdew-Burke-Ernzerhof (PBE) exchange-correlation energy functional. Minimum energy structures of the gold cluster along with their isomers are considered in the optimization process. H 2 S molecule is observed to adsorb on to the gold cluster. However, the adsorption energy decreases with increasing cluster size. The structure of the gold clusters are similar before and after adsorption of H 2 S molecule. The structure of gold cluster remain planar. The adsorbed molecule get adjusted in a way that their center of mass lie on the plane of the gold cluster. The adsorbed molecules get attached to a single gold atom and there is no preference to get adsorbed in between the gold. H 2 S dissociation is not favoured on the Au clusters.