Gold, Copper, and Platinum Nanoparticles Dispersed on CeO/TiO(110) Surfaces: High Water-Gas Shift Activity and the Nature of the Mixed-Metal Oxide at the Nanometer Level.
At small coverages of ceria on TiO(110), the CeO nanoparticles have an unusual coordination mode. Scanning tunneling microscopy and density-functional calculations point to the presence of CeO dimers, which form diagonal arrays that have specific orientations of 0, 24, and 42° with respect to the [1...
| Published in: | Journal of the American Chemical Society Vol. 132; no. 1; pp. 356 - 364 |
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| Main Authors: | , , , , , , , , , |
| Format: | Article |
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American Chemical Society
1/13/2010
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| Subjects: | |
| Online Access: | View this record in EBSCOhost |
| fields | @attributes: recordID: 1 pdfLink: plink: https://search.ebscohost.com/login.aspx?direct=true&db=hlh&AN=48230231&site=ehost-live header: @attributes: shortDbName: hlh uiTerm: 48230231 longDbName: Humanities International Complete uiTag: AN controlInfo: bkinfo: jinfo: jid: 00027863 ACS jtl: Journal of the American Chemical Society issn: 00027863 maglogo: N pubinfo: dt: 1/13/2010 vid: 132 iid: 1 pid: 997 pub: American Chemical Society artinfo: ui: 48230231 10.1021/ja9087677 ppf: 356 ppct: 8 formats: tig: atl: Gold, Copper, and Platinum Nanoparticles Dispersed on CeO/TiO(110) Surfaces: High Water-Gas Shift Activity and the Nature of the Mixed-Metal Oxide at the Nanometer Level. aug: au: Park, Joon B. Graciani, Jesus Evans, Jaime Stacchiola, Dario Senanayake, Sanjaya D. Barrio, Laura Ping Liu Fdez. Sanz, Javier Hrbek, Jan Rodriguez, José A. affil: Chemistry Department, Brookhaven National Laboratory, Upton, New York 11973 Institute of Fusion Science, Department of Chemistry Education, Chonbuk National University, Jeonju, Jeonbuk 561-756, South Korea Departamento de Química Física, Universidad de Sevilla, E-41012 Seville, Spain Facultad de Ciencias, Universidad Central de Venezuela, Caracas 1020 A, Venezuela Department of Chemistry, Michigan Technological University, Houghton, MI 49931 su: Cerium oxides Nanoparticles Scanning tunneling microscopy Density functionals Gold Copper Platinum sug: subj: Cerium oxides Nanoparticles Scanning tunneling microscopy Density functionals Gold Copper Platinum ab: At small coverages of ceria on TiO(110), the CeO nanoparticles have an unusual coordination mode. Scanning tunneling microscopy and density-functional calculations point to the presence of CeO dimers, which form diagonal arrays that have specific orientations of 0, 24, and 42° with respect to the [1-10] direction of the titania substrate. At high coverages of ceria on TiO(110), the surface exhibits two types of terraces. In one type, the morphology is not very different from that observed at low ceria coverage. However, in the second type of terrace, there is a compact array of ceria particles with structures that do not match the structures of CeO(111) or CeO(110). The titania substrate imposes on the ceria nanoparticles nontypical coordination modes, enhancing their chemical reactivity. This phenomenon leads to a larger dispersion of supported metal nanoparticles (M = Au, Cu, Pt) and makes possible the direct participation of the oxide in catalytic reactions. The M/CeO/TiO(110) surfaces display an extremely high catalytic activity for the water-gas shift reaction that follows the sequence Au/CeO/TiO(110) < Cu/CeO/TiO(110) < Pt/ CeO/TiO(110). For low coverages of Cu and CeO, Cu/CeO/TiO(110) is 8-12 times more active than Cu(111) or Cu/ZnO industrial catalysts. In the M/CeO/TiO(110) systems, there is a strong coupling of the chemical properties of the admetal and the mixed-metal oxide: The adsorption and dissociation of water probably take place on the oxide, CO adsorbs on the admetal nanoparticles, and all subsequent reaction steps occur at the oxide-admetal interface. The high catalytic activity of the M/CeO/TiO(110) surfaces reflects the unique properties of the mixed-metal oxide at the nanometer level. pubtype: Academic Journal doctype: Article src: R language: English refInfo: copyright: @attributes: flag: Y dt: @attributes: year: 2010 holdings: @attributes: islocal: N |
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