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Title: Effect of reducible oxide–metal cluster charge transfer on the structure and reactivity of adsorbed Au and Pt atoms and clusters on anatase TiO 2

Authors:
 [1];  [2];  [3]
  1. Department of Chemistry, Princeton University, Princeton, New Jersey 08544, USA, State Key Laboratory of Organic Geochemistry and Guangdong Provincial Key Laboratory of Environmental Protection and Resources Utilization, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China, University of Chinese Academy of Sciences, Beijing 100049, China
  2. State Key Laboratory of Organic Geochemistry and Guangdong Provincial Key Laboratory of Environmental Protection and Resources Utilization, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China, Guangzhou Key Laboratory of Environmental Catalysis and Pollution Control, School of Environmental Science and Engineering, Institute of Environmental Health and Pollution Control, Guangdong University of Technology, Guangzhou 510006, China
  3. Department of Chemistry, Princeton University, Princeton, New Jersey 08544, USA
Publication Date:
Sponsoring Org.:
USDOE
OSTI Identifier:
1361868
Grant/Contract Number:
SC0007347
Resource Type:
Journal Article: Publisher's Accepted Manuscript
Journal Name:
Journal of Chemical Physics
Additional Journal Information:
Journal Volume: 146; Journal Issue: 18; Related Information: CHORUS Timestamp: 2018-02-14 09:56:23; Journal ID: ISSN 0021-9606
Publisher:
American Institute of Physics
Country of Publication:
United States
Language:
English

Citation Formats

Wang, Honghong, An, Taicheng, and Selloni, Annabella. Effect of reducible oxide–metal cluster charge transfer on the structure and reactivity of adsorbed Au and Pt atoms and clusters on anatase TiO 2. United States: N. p., 2017. Web. doi:10.1063/1.4982933.
Wang, Honghong, An, Taicheng, & Selloni, Annabella. Effect of reducible oxide–metal cluster charge transfer on the structure and reactivity of adsorbed Au and Pt atoms and clusters on anatase TiO 2. United States. doi:10.1063/1.4982933.
Wang, Honghong, An, Taicheng, and Selloni, Annabella. Sun . "Effect of reducible oxide–metal cluster charge transfer on the structure and reactivity of adsorbed Au and Pt atoms and clusters on anatase TiO 2". United States. doi:10.1063/1.4982933.
@article{osti_1361868,
title = {Effect of reducible oxide–metal cluster charge transfer on the structure and reactivity of adsorbed Au and Pt atoms and clusters on anatase TiO 2},
author = {Wang, Honghong and An, Taicheng and Selloni, Annabella},
abstractNote = {},
doi = {10.1063/1.4982933},
journal = {Journal of Chemical Physics},
number = 18,
volume = 146,
place = {United States},
year = {Sun May 14 00:00:00 EDT 2017},
month = {Sun May 14 00:00:00 EDT 2017}
}

Journal Article:
Free Publicly Available Full Text
Publisher's Version of Record at 10.1063/1.4982933

Citation Metrics:
Cited by: 2works
Citation information provided by
Web of Science

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  • To probe metal particle/reducible oxide interactions Density Functional Theory based Ab Initio Molecular Dynamics studies were performed on a prototypical metal cluster (Au 20) supported on reducible oxides (rutile TiO 2(110)) to implicitly account for finite temperature effects and the role of excess surface charge in the metal oxide. It was found that the charge state of the Au particle is negative in a reducing chemical environment whereas in the presence of oxidizing species co-adsorbed to the oxide surface the cluster obtained a net positive charge. In the context of the well known CO oxidation reaction, charge transfer facilitates themore » plasticization of Au 20 which allows for a strong adsorbate induced surface reconstruction upon addition of CO leading to the formation of mobile Au-CO species on the surface. The charging/discharging of the cluster during the catalytic cycle of CO oxidation enhances and controls the amount of O 2 adsorbed at oxide surface/cluster interface and strongly influences the energetics of all redox steps in catalytic conversions. A detailed comparison of the current findings with previous studies is presented and generalities about the role of surface-adsorbate charge transfer for metal cluster/reducible oxide interactions are discussed.« less
  • Fast atom bombardment mass spectroscopy has been used to examine a large number of cationic phosphine-containing transition-metal-fold clusters including polyhydrides, which ranged in mass from 1000 to 4000. Many of these clusters have been previously characterized and were examined in order to test the usefulness of the FABMS technique. Results showed that FABMS is excellent in giving the correct molecular formula including the number of hydride ligands, and when combined with NMR, conductance and analytical data gave complete and reliable characterization. Four new complexes have been synthesized and completely characterized by the above techniques. These are (Au/sub 2/Pt(PPh/sub 3/)/sub 4/NO/submore » 3/)NO/sub 3/, (Au/sub 6/Pt(PPh/sub 3/)/sub 7/)(BPh/sub 4/)/sub 2/, (Au/sub 2/Re/sub 2/(H)/sub 6/(PPh/sub 3/)/sub 6/)PF/sub 6/, and (Au/sub 4/Re(H)/sub 4/(P(p-tol)/sub 3/)/sub 2/(PPh/sub 3/)/sub 4/)PF/sub 6/. The FABMS of these and other similar cationic and dicationic clusters with use of m-nitrobenzyl alcohol (MNBA) as the matrix always gave well-resolved peaks for either the parent molecular ion (M)/sub 7/ or the ion pair (M + X)/sup +/ where X = the counterion. Comparison of observed and calculated isotopic ion distributions for these peaks reliably gave the correct molecular formulas. Cluster fragments were also observed that in general resulted from loss of one or more of the following species: PPh/sub 3/, H, CO, Ph, AuPPh/sub 3/. Small peaks that resulted from the addition of matrix fragments to unsaturated cluster ions were also observed.« less
  • We show how CO 2 adsorption on perfect and reduced anatase TiO 2 (101) surfaces can be substantially modified by the presence of surface Ag and Pt octamer clusters, using density functional theory calculations. Furthermore, we found that adsorption was affected even at sites where the adsorbate was not in direct contact with the octamer, which we attributed to charge donation to CO 2 from the Ag/Pt-modified surface, as well as an electrostatic competition between attractive (Ti–O) and repulsive (Ti–C) interactions. Additionally, TiO 2-supported Pt octamers offer key advantages that could be leveraged for CO 2 photoreduction, including providing additionalmore » stable adsorption sites for bent CO 2 species and facilitating charge transfer to aid in CO 2– anion formation. Electronic structure analysis suggests these factors arise primarily from the hybridization of the bonding molecular orbitals of CO 2 with d orbitals of the Pt atoms. Our results show that, for adsorption on TiO 2-supported Pt octamers, the O–C–O bending and C–O asymmetric stretching frequencies can be used as reliable indicators of the presence of the CO 2– anion intermediate as well as to distinguish unique adsorption geometries or sites. Finally, we suggest a possible pathway for subsequent CO 2 dissociation to CO at the surface of a reduced anatase TiO 2 (101)-supported Pt octamer, which has a computed energy barrier of 1.01 eV.« less
  • The results of a detailed study of Li{sup +} neutralization in scattering on Ag and Au clusters and thin films supported on TiO{sub 2} are presented. A very efficient neutralization is observed on small clusters with a decrease for the smallest clusters. These results closely follow the size-effects observed in the reactivity of these systems. The energy dependence of the neutralization was studied for the larger clusters (>4 nm) and observed to be similar in trend to the one observed on films and bulk (111) crystals. A general discussion of possible reasons of the enhancement in neutralization is presented andmore » these changes are then tentatively discussed in terms of progressive modifications in the electronic structure of clusters as a function of reduction in size and as it evolves from metallic-like to discretised states. The highest neutralization efficiency would appear to correspond to clusters sizes for which a metal to nonmetal transition occurs. The relative position of the Li level and the highest occupied molecular orbital in the molecular cluster can be expected to strongly affect the electron transfer processes, which in this case should be described in a molecular framework.« less