Probing the structural, electronic, and adsorptive properties of Au16O2- clusters

Great progress has been made in O-2 adsorption on gold clusters. However, systematic investigations of O-2 adsorption on Au-16(-) clusters have not been reported. Here, we present a systematic study of the structural, electronic, and adsorptive properties of Au16O2- clusters by density functional theory (DFT) calculations coupled with stochastic kicking method. Global minimum searches for Au16O2- reveal that exohedral derivatives are more favored. Furthermore, the obtained ground-state structure exhibits significant stability, as judged by its larger adsorption energy (1.16 eV) and a largerHOMO-LUMO gap (0.57 eV). The simulated photoelectron spectra (PES) of Au16O2- isomers will be instructive to identify the structures in future experiments. There are three interesting discoveries in the present paper: (1) O-2 undergoes chemical adsorption onto the parent Au-16(-) clusters, but the amount of the adsorption energy is related to the parent Au-16(-) clusters; (2) the process that O-2 undergoes dissociative adsorption onto the parent Au- 16 clusters is exothermic; (3) Au16O2- isomers show smaller X-A energy gaps than those of parent Au-16(-) clusters, reflecting that their geometric and electronic structures are distorted remarkably due to dissociative adsorption of O-2.