Oxidation-resistant gold-55 clusters.
Gold nanoparticles ranging in diameter from 1 to 8 nanometers were prepared on top of silicon wafers in order to study the size dependence of their oxidation behavior when exposed to atomic oxygen. X-ray photoelectron spectroscopy showed a maximum oxidation resistance for "magic-number" clusters containing 55 gold atoms. This inertness is not related to electron confinement leading to a size-induced metal-to-insulator transition, but rather seems to be linked to the closed-shell structure of such magic clusters. The result additionally suggests that gold-55 clusters may act as especially effective oxidation catalysts, such as for oxidizing carbon monoxide.
Abteilung Festkörperphysik, Abteilung Organische Chemie III, Universität Ulm, D-89069 Ulm, Germany. hans-gerd.boyen@physik.uni-ulm.de
H-G
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Boyen
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Kästle
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Weigl
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B
Koslowski
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Dietrich
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Ziemann
J P
JP
Spatz
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Riethmüller
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Hartmann
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Möller
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Schmid
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Garnier
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Oelhafen