Probing the structural, electronic, and adsorptive properties of Au16O2– clusters.

Great progress has been made in O₂ adsorption on gold clusters. However, systematic investigations of O₂ adsorption on Au 16 − clusters have not been reported. Here, we present a systematic study of the structural, electronic, and adsorptive properties of Au 16 O 2 – clusters by density functional theory (DFT) calculations coupled with stochastic kicking method. Global minimum searches for Au 16 O 2 – 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 larger HOMO-LUMO gap (0.57 eV). The simulated photoelectron spectra (PES) of Au 16 O 2 – isomers will be instructive to identify the structures in future experiments. There are three interesting discoveries in the present paper: (1) O₂ 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 O₂ undergoes dissociative adsorption onto the parent Au 16 − clusters is exothermic; (3) Au 16 O 2 – 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 O₂. [ABSTRACT FROM AUTHOR]