title: Mild activation of CeO2-supported gold nanoclusters and insight into the catalytic behavior in CO oxidation.
abstract: We report a new activation method and insight into the catalytic behavior of a CeO2-supported, atomically precise Au144(SR)60 nanocluster catalyst (where thiolate -SR = -SCH2CH2Ph) for CO oxidation. An important finding is that the activation of the catalyst is closely related to the production of active oxygen species on CeO2, rather than ligand removal of the Au144(SR)60 clusters. A mild O2 pretreatment (at 80 °C) can activate the catalyst, and the addition of reductive gases (CO or H2) can enhance the activation effects of O2 pretreatment via a redox cycle in which CO could reduce the surface of CeO2 to produce oxygen vacancies-which then adsorb and activate O2 to produce more active oxygen species. The CO/O2 pulse experiments confirm that CO is adsorbed on the cluster catalyst even with ligands on, and active oxygen species present on the surface of the pretreated catalyst reacts with CO pulses to generate CO2. The Au144(SR)60/CeO2 exhibits high CO oxidation activity at 80 °C without the removal of thiolate ligands. The surface lattice-oxygen of the support CeO2 possibly participates in the oxidation of CO over the Au144(SR)60/CeO2 catalyst.
authors.affiliation: Dalian National Laboratory for Clean Energy, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, China. geqj@dicp.ac.cn and University of Chinese Academy of Sciences, Beijing 100049, China.
authors.forename: Weili
authors.initials: W
authors.lastname: Li
authors.affiliation: Dalian National Laboratory for Clean Energy, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, China. geqj@dicp.ac.cn.
authors.forename: Qingjie
authors.initials: Q
authors.lastname: Ge
authors.affiliation: Dalian National Laboratory for Clean Energy, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, China. geqj@dicp.ac.cn.
authors.forename: Xiangang
authors.initials: X
authors.lastname: Ma
authors.affiliation: Department of Chemistry, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213, USA. rongchao@andrew.cmu.edu.
authors.forename: Yuxiang
authors.initials: Y
authors.lastname: Chen
authors.affiliation: Department of Chemistry, Anhui University, Hefei 230026, China.
authors.forename: Manzhou
authors.initials: M
authors.lastname: Zhu
authors.affiliation: Dalian National Laboratory for Clean Energy, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, China. geqj@dicp.ac.cn.
authors.forename: Hengyong
authors.initials: H
authors.lastname: Xu
authors.affiliation: Department of Chemistry, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213, USA. rongchao@andrew.cmu.edu.
authors.forename: Rongchao
authors.initials: R
authors.lastname: Jin