title: Stable and solubilized active Au atom clusters for selective epoxidation of cis-cyclooctene with molecular oxygen.
abstract: The ability of Au catalysts to effect the challenging task of utilizing molecular oxygen for the selective epoxidation of cyclooctene is fascinating. Although supported nanometre-size Au particles are poorly active, here we show that solubilized atomic Au clusters, present in ng ml-1concentrations and stabilized by ligands derived from the oxidized hydrocarbon products, are active. They can be formed from various Au sources. They generate initiators and propagators to trigger the onset of the auto-oxidation reaction with an apparent turnover frequency of 440 s-1, and continue to generate additional initiators throughout the auto-oxidation cycle without direct participation in the cycle. Spectroscopic characterization suggests that 7-8 atom clusters are effective catalytically. Extension of work based on these understandings leads to the demonstration that these Au clusters are also effective in selective oxidation of cyclohexene, and that solubilized Pt clusters are also capable of generating initiators for cyclooctene epoxidation.
authors.affiliation: Department of Chemistry and Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials, Fudan University, Shanghai 200433, China.|School of Materials Science and Engineering, Northwestern Polytechnical University, Xi'an, Shaansi 710072, China.
authors.forename: Linping
authors.initials: L
authors.lastname: Qian
authors.affiliation: School of Materials Science and Engineering, Northwestern Polytechnical University, Xi'an, Shaansi 710072, China.|Chemical and Biological Engineering Department, Northwestern University, Evanston, Illinois 60208, USA.
authors.forename: Zhen
authors.initials: Z
authors.lastname: Wang
authors.affiliation: School of Materials Science and Engineering, Northwestern Polytechnical University, Xi'an, Shaansi 710072, China.
authors.forename: Evgeny V
authors.initials: EV
authors.lastname: Beletskiy
authors.affiliation: Physics Department, Arizona State University, Tempe, Arizona 85281, USA.
authors.forename: Jingyue
authors.initials: J
authors.lastname: Liu
authors.affiliation: School of Materials Science and Engineering, Northwestern Polytechnical University, Xi'an, Shaansi 710072, China.|Instituto de Química, Universidade Federal da Bahia, Campus Ondina, Federação, Salvador 40170-280, Bahia, Brazil.|Instituto Federal de Educação, Ciência e Tecnológica da Bahia, Eunápolis 45820-970, Bahia, Brazil.
authors.forename: Haroldo J
authors.initials: HJ
authors.lastname: Dos Santos
authors.affiliation: Chemical and Biological Engineering Department, Northwestern University, Evanston, Illinois 60208, USA.
authors.forename: Tiehu
authors.initials: T
authors.lastname: Li
authors.affiliation: Instituto de Química, Universidade Federal da Bahia, Campus Ondina, Federação, Salvador 40170-280, Bahia, Brazil.
authors.forename: Maria do C
authors.initials: MD
authors.lastname: Rangel
authors.affiliation: School of Materials Science and Engineering, Northwestern Polytechnical University, Xi'an, Shaansi 710072, China.
authors.forename: Mayfair C
authors.initials: MC
authors.lastname: Kung
authors.affiliation: School of Materials Science and Engineering, Northwestern Polytechnical University, Xi'an, Shaansi 710072, China.
authors.forename: Harold H
authors.identifier: 0000-0001-9599-0155
authors.initials: HH
authors.lastname: Kung