Density functional study of H2S binding on small cationic (n + m ⩽ 5) clusters

Density functional theory calculations were performed to investigate the structural and energetic properties of H2S binding on small cationic Ag n Au m + clusters (n + m ⩽ 5). The adsorbates prefer binding to Au atoms when both Au and Ag co-exist in the cluster with the exceptions of Ag4Au+ and Ag 3 Au 2 + . The binding energy decreases as the cluster size grows and is further correlated with the LUMO energy of bare Ag n Au m + clusters. Our calculation suggests that the Ag n Au m + cations may react with H2S dissociatively by way of a H2 molecule loss. The SH and MS vibrational frequencies are highly related to whether S atom is attached to Au or Ag atoms.