Probing the Interactions of O2 with Small Gold Cluster Au n Q (n = 2–10, Q = 0, −1): A Neutral Chemisorbed Complex Au5O2 Cluster Predicted

• Published in: Journal of physical chemistry. C Vol. 121; no. 44; pp. 24886 - 24893
• Main Authors: Shi, Hong Xiao, Sun, Wei Guo, Kuang, Xiao Yu, Lu, Cheng, Xia, Xin Xin, Chen, Bo Le, Hermann, Andreas
• Format: Journal Article
• Language: English
• Published: American Chemical Society 09.11.2017
• ISSN: 1932-7447; 1932-7455
• DOI: 10.1021/acs.jpcc.7b09022

Enormous progress has been made in catalytic oxidation reactions involving nanosized gold particles. However, the reaction mechanism of O2 with neutral gold clusters remains complicated. Here, we have performed an unbiased structure search for Au n Q and Au n O2 Q (n = 2–10, Q = 0, −1) clusters by means of CALYPSO structure searching method. Subsequently, the lowest-energy candidate structures were fully optimized at the B3PW91/Au/LANL2DZ/O/6-311+G­(d) level of theory to determine the global minimum structures. Based on the ground-state structures of Au n – and Au n O2 – (n = 2–10), we have simulated the photoelectron spectra (PES) using time-dependent density functional theory. The good agreement between simulated PES and the corresponding experimental data suggest that the current ground-state structures are the true minima. The locally maximized value of the adsorption energy in Au5O2, where the unpaired electron of Au5 can transfer to O2, makes it the most promising candidate of the chemisorbed complex. A comprehensive analysis of molecular orbitals and chemical bonding of the Au5O2 cluster reveals that O2 can be chemisorbed onto the neutral Au5 cluster.