Positive Charge States and Possible Polymorphism of Gold Nanoclusters on Reduced Ceria.

The catalytic properties of Au/CeO systems are sensitive to the nature of Au clusters; however, atomic information on Au clusters is sparse. In this work, we use density functional theory to investigate the nucleation of small Au clusters (up to Au). By depositing Au atoms one by one at a reduced Ce...

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Detalles Bibliográficos
Publicado en:Journal of the American Chemical Society Vol. 132; no. 7; pp. 2175 - 2183
Autores principales: Changjun Zhang, MichaeIides, Angelos, King, David A., Jenkins, Stephen J.
Formato: Artículo
Publicado: American Chemical Society 2/24/2010
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Acceso en línea:Ver este registro en EBSCOhost
Descripción
Sumario:The catalytic properties of Au/CeO systems are sensitive to the nature of Au clusters; however, atomic information on Au clusters is sparse. In this work, we use density functional theory to investigate the nucleation of small Au clusters (up to Au). By depositing Au atoms one by one at a reduced CeO(111 surface, we present detailed nucleation patterns. Although relatively small in size, the nanoclusters obtained exhibit interesting characteristic features. In addition to the face-centered cubic (fcc) geometry, reminiscent of bulk Au, we also find the existence of novel hexagonal close-packed (hcp) structures. Furthermore, the facets of the nanoclusters are versatile, comprising (111 )/(100) combinations for the fcc-like clusters and (10l )/(0001 ) combinations for the hcp-like. Electronically, the contact layer Au atoms that bond with surface 0 atoms are positively charged, which could have significant implications in catalysis.