Chemical properties of mass-selected coinage metal cluster anions: towards obtaining molecular-level understanding of nanocatalysis

Kim, Young Dok

doi:10.1016/j.ijms.2004.08.001

Cited by 41 publications

(21 citation statements)

References 108 publications

(176 reference statements)

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“…[53] Many of these and other questions have also been addressed in gas-phase experiments on free gold clusters,a nd the results have been reviewed repeatedly. [3,5,10,14,54,55] Here,Iwill briefly mention the remarkable effects of asingle gold atom attached to three different metal-oxide cluster ions,a ss tudied experimentally and computationally by He and co-workers. [56][57][58] CO oxidation according to Eq.…”

Section: Angewandte Minireviewsmentioning

confidence: 99%

Doping Effects in Cluster‐Mediated Bond Activation

2015

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Gas-phase investigations of judiciously doped oxide clusters permit to address fundamental challenges related to, for example, the low-temperature oxidation of CO or the selective conversion of hydrocarbons. Modifying the size and composition of a free cluster in a controlled way enables the modification of local charge effects and of spin states, and spectroscopic studies in combination with computational work help to identify the active site of a catalyst and to unravel mechanistic details. Also, the interplay of the support material with the reactive part of a composite catalyst cluster can be addressed. Examples will be presented demonstrating how and why the gas-phase reactivities of heteronuclear clusters, in comparison with their homonuclear counterparts, toward small, generally rather inert molecules can be increased, decreased, or not significantly affected.

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Section: Angewandte Minireviewsmentioning

confidence: 99%

Doping Effects in Cluster‐Mediated Bond Activation

2015

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“…Furthermore, massselected cluster studies, employing tandem mass spectrometry, enable the influence of factors such as size, stoichiometry, and ionic charge state on cluster reactivity to be determined with atomic-level precision (35). For nanocatalysis, this is extremely relevant because the reactive properties of clusters have been observed to change dramatically with the addition or removal of single atoms (37). Charging effects have also been shown to exert a pronounced influence on the activity of supported catalyst particles (38,39).…”

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Cluster reactivity experiments: Employing mass spectrometry to investigate the molecular level details of catalytic oxidation reactions

Johnson

Tyo

Castleman

2008

Proc. Natl. Acad. Sci. U.S.A.

117

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Mass spectrometry is the most widely used tool in the study of the properties and reactivity of clusters in the gas phase. In this article, we demonstrate its use in investigating the molecular-level details of oxidation reactions occurring on the surfaces of heterogeneous catalysts via cluster reactivity experiments. Guided ion beam mass spectrometry (GIB-MS) employing a quadrupole-octopolequadrupole (Q-O-Q) configuration enables mass-selected cluster ions to be reacted with various chemicals, providing insight into the effect of size, stoichiometry, and ionic charge state on the reactivity of catalyst materials. For positively charged tungsten oxide clusters, it is shown that species having the same stoichiometry as the bulk, WO 3 ؉ , W2O 6 ؉ , and W3O 9 ؉ , exhibit enhanced activity and selectivity for the transfer of a single oxygen atom to propylene (C 3H6), suggesting the formation of propylene oxide (C 3H6O), an important monomer used, for example, in the industrial production of plastics. Furthermore, the same stoichiometric clusters are demonstrated to be active for the oxidation of CO to CO 2, a reaction of significance to environmental pollution abatement. The findings reported herein suggest that the enhanced oxidation reactivity of these stoichiometric clusters may be due to the presence of radical oxygen centers (W-O•) with elongated metal-oxygen bonds. The unique insights gained into bulk-phase oxidation catalysis through the application of mass spectrometry to cluster reactivity experiments are discussed.catalysis ͉ tungsten oxide ͉ oxygen radical ͉ carbon monoxide ͉ propylene M ass spectrometry has been crucial to the field of cluster research since its inception (1-9). A variety of cluster formation methods, primarily including laser vaporization (LaVa) (10-12), pulsed-arc discharge (PACIS) (13-15), electrospray ionization (ESI) (16), gas aggregation (17-18), and inert gas sputtering (CORDIS) (18) have enabled the creation of both positively and negatively charged as well as neutral gas-phase clusters across a large size range and with diverse elemental composition. The thermodynamic properties of clusters, including bond-dissociation energies (19-21), endothermic-reaction barriers (22), heat capacities (23), and the enthalpy, entropy, and free-energy changes associated with clustering reactions (24, 25), including those composed of hydrogen-bonded and van der Waals systems, have been widely studied, employing both GIB-MS and flow-tube experiments. Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR) (26) along with other linear ion trapping techniques (27) have been used to investigate the time-dependent kinetics of cluster molecule reactions, providing insight into reaction mechanisms, activation energies, and reaction intermediates. The structural properties of clusters, including bonding motifs and collision cross-sections have been examined through collision-induced dissociation (CID) (28) and high-pressure drift cell experiments (29). Time-of-flight (TOF) mass spectrometry...

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“…Viele dieser und anderer Fragen wurden auch in Gasphasenexperimenten an freien Goldclustern studiert, und die Ergebnisse wurden mehrfach zusammengefasst 3. 5, 10, 14, 54, 55 An dieser Stelle soll der von He und Mitarbeitern sowohl experimentell als auch durch Rechnungen studierte, bemerkenswerte Effekt eines einzelnen Goldatoms erwähnt werden, das jeweils an drei verschiedene ionische Metalloxidcluster gebunden ist 56–58…”

Section: Co‐oxidation Unter Normalbedingungenunclassified

Dotierungseffekte bei Cluster‐vermittelten Bindungsaktivierungen

Schwarz

2015

Angewandte Chemie

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Chemical properties of mass-selected coinage metal cluster anions: towards obtaining molecular-level understanding of nanocatalysis

Cited by 41 publications

References 108 publications

Doping Effects in Cluster‐Mediated Bond Activation

Doping Effects in Cluster‐Mediated Bond Activation

Cluster reactivity experiments: Employing mass spectrometry to investigate the molecular level details of catalytic oxidation reactions

Dotierungseffekte bei Cluster‐vermittelten Bindungsaktivierungen

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