Journal ArticleDOI
Chemical reactivity of size-selected supported clusters: An experimental setup
TLDR
In this paper, an experimental setup for the investigation of the chemical reactivity of size-selected, supported clusters is described, where the clusters are generated by a high frequency laser vaporization source, and after mass selection and energy control, they are deposited under ultrahigh-vacuum conditions and with low kinetic energy onto thin oxide films grown on metal single crystals.Abstract:
We describe an experimental setup for the investigation of the chemical reactivity of size-selected, supported clusters. The clusters are generated by a high frequency laser vaporization source. After mass selection and energy control the clusters are deposited under ultrahigh-vacuum conditions and with low kinetic energy onto thin oxide films grown on metal single crystals. Such films are ideal in their function as supports for size-selected deposited metal clusters. Measured currents of mass-selected niobium cluster ions were of the order of 1 nA and are high enough for fast deposition rates. Adsorbed molecules used on the one hand as probes to characterize the supported clusters and on the other hand for studying chemical reactions on these clusters are investigated in situ by Fourier transform infrared spectroscopy, temperature desorption spectroscopy, and Auger electron spectroscopy. The performance of these analytical tools is illustrated with CO adsorbed on Ni atoms supported on thin MgO(100) films...read more
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Journal ArticleDOI
When Gold Is Not Noble: Nanoscale Gold Catalysts
A. Sanchez,Stéphane Abbet,Ueli Heiz,Wolf-Dieter Schneider,Hannu Häkkinen,Robert N. Barnett,Uzi Landman +6 more
TL;DR: In this article, temperature-programmed reaction studies of the catalyzed combustion of CO on size-selected small monodispersed Aun (n ≤ 20) gold clusters supported on magnesia, and first-principle simulations reveal the microscopic origins of the observed unusual catalytic activity, with Au8 being the smallest catalytically active size.
Journal ArticleDOI
Metal deposits on well-ordered oxide films
TL;DR: In this paper, the authors discuss the possibility to use thin, well-ordered oxide films as supports for the study of deposited metal particles, which offers the advantage to permit the unrestricted application of all experimental methods, which rely on a good electrical or thermal conductivity of the sample, like PES, LEED, STM or TDS.
Journal ArticleDOI
Interaction of nanostructured metal overlayers with oxide surfaces
Qiang Fu,Thomas Wagner +1 more
TL;DR: In this paper, a review of metal-oxide interfaces at temperatures below 1000 ǫC is presented, with special emphasis on model systems like ultrathin metal overlayers or metal nanoclusters supported on well-defined oxide surfaces.
Journal ArticleDOI
The structures of small gold cluster anions as determined by a combination of ion mobility measurements and density functional calculations
Filipp Furche,Reinhart Ahlrichs,Patrick Weis,Christoph R. Jacob,Stefan Gilb,Thomas Bierweiler,Manfred M. Kappes +6 more
TL;DR: In this article, a combined experimental and theoretical study of small gold cluster anions is performed, where the experimental effort consists of ion mobility measurements that lead to the assignment of the collision cross sections for the different cluster sizes at room temperature and the theoretical study is based on abomolecular dynamics calculations with the goal to find energetically favorable candidate structures.
Journal ArticleDOI
Catalytic oxidation of carbon monoxide on monodispersed platinum clusters: Each atom counts
TL;DR: In this paper, the authors investigated the catalytic reaction that is the oxidation of CO on platinum and observed a distinct atom by atom size dependency for monodispersed platinum clusters on thin MgO(100) films.
References
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Journal ArticleDOI
Infrared reflection-absorption spectroscopy of adsorbed molecules
TL;DR: Theoretical and experimental aspects of this method in a single reflection mode are discussed in this paper, where vibrational frequencies of the C-O stretch allow determination of adsorption sites.
Journal ArticleDOI
Nucleation in Very Rapid Vapor Expansions
TL;DR: In this article, an approximate lower bound for the time (nucleation time) required for the formation of this system of embryos can be calculated by neglecting the thermodynamic barrier which impedes their formation.
Journal ArticleDOI
Controlled deposition of size-selected silver nanoclusters
TL;DR: Variable-temperature scanning tunneling microscopy was used to study the effect of kinetic cluster energy and rare-gas buffer layers on the deposition process of size-selected silver nanoclusters on a platinum(111) surface, finding that nondestructive cluster deposition represents a promising method to produce monodispersed nanostructures at surfaces.