Electronic structure of deposited monosized metal-clusters

Cox, D. M.; Eberhardt, W.; Fayet, Pierre; Fu, Z.; Keßler, Barbara; Sherwood, R. D.; Sondericker, D.; Kaldor, A.

doi:10.1007/bf01544017

Cited by 28 publications

(19 citation statements)

References 3 publications

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“…21 Bilayer clusters has also been proposed by Herzing et al for AuFe coprecipitates dried at 393 K. 62 The deposition of gold clusters onto Si(100) wafers with a natural oxide-layer enabled X-ray photoelectron spectroscopy measurements of Au 1 to Au 7 clusters. 63 The fine-structure splitting between the 5d 5/2 and the 5d 3/2 with the bulk value, 2.55 eV, decreased with a decrease in the number of gold atoms. to Au + during CO oxidation.…”

Section: ¹1mentioning

confidence: 95%

Size- and Structure-specificity in Catalysis by Gold Clusters

2014

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Although gold in bulk is poorly active as a catalyst, it exhibits surprisingly high catalytic activity when deposited as nanoparticles (NPs) on base metal oxides. The catalytic performance of supported gold NPs can be created by choosing the kind of support materials, by controlling the size of gold, and by building up strong contact of gold with the supports. Since perimeter interfaces around gold NPs act, in principle, as the active sites for oxidation and hydrogenation, gold should be smaller than 10 nm in diameter. A new area of research is clusters, which are smaller than 2 nm in diameter and less than 200 atoms. Gold clusters possess electronic structures different from those of bulk gold and at the same time provide increased fractions of edges and corners which are highly unsaturatedly coordinated sites. Accordingly, gold clusters will be blessed by unique catalytic performance, and many examples have recently been emerging. This article summarizes such examples in terms of "size-and structure-specificity," covering gas-phase free clusters, polymer-or organic-ligand-stabilized clusters in liquid phase, and clusters supported on base metal oxides, carbon materials, and organic polymers for gas-phase and liquid-phase reactions.

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Section: ¹1mentioning

confidence: 95%

Size- and Structure-specificity in Catalysis by Gold Clusters

2014

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“…This offset, in the present case, strongly points to the presence of single Au atoms or small clusters (dimers, trimers, etc. [19,20] ). During the photoionization process these clusters are charged and, as a consequence of their small, size-dependent electrical capacitance, a significant energy loss of the escaping photoelectron (final-state effect [21] ) is observed, leading to the above mentioned offset.…”

Section: Formation and Chemical State Of The Nanoparticlesmentioning

confidence: 99%

Micellar Nanoreactors—Preparation and Characterization of Hexagonally Ordered Arrays of Metallic Nanodots

Kästle

Boyen

Weigl

et al. 2003

Adv Funct Materials

220

217

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The preparation of hexagonally ordered metallic nanodots was studied in detail with emphasis on the chemical state of the resulting particles. To obtain these dots, in a first step micellar structures were formed from diblock copolymers in solution. The reverse micelles themselves are capable of ligating defined amounts of a metal salt within their cores, acting as nanoreactors. After transfer of the metal‐loaded reverse micelles onto a substrate, the polymer was removed by means of different plasmas (oxygen and/or hydrogen), which also allow the metal salt to be reduced to the metallic state. In this way, ordered arrays of metallic nanodots can be prepared on various substrates. By adjusting the appropriate parameters, the separation and the size of the dots can be varied and controlled. To determine their purity, chemical state, and surface cleanliness—all of which are crucial for subsequent experiments since nanoscale structures are intrinsically surface dominated—in‐situ X‐ray photoelectron spectroscopy (XPS) and ex‐situ transmission electron microscopy (TEM) were applied, also giving information on the formation of the nanodots.

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“…In X-ray photoelectron spectroscopy (XPS) of Au nanoparticles, Au 4f-binding energy shifts toward higher energy from a bulk value, depending on Au particle size [1][2][3][4][5][6][7][8]. The Au particle size can be, therefore, deduced from the Au 4f-binding energy shift.…”

Section: Introductionmentioning

confidence: 99%