Ag-Cu alloy surfaces in an oxidizing environment: a first-principles study (Articolo in rivista)

Type

• Prodotto della ricerca (Classe)
• Articolo in rivista (Classe)

Label

• Ag-Cu alloy surfaces in an oxidizing environment: a first-principles study (Articolo in rivista) (literal)

Anno

• 2009-01-01T00:00:00+01:00 (literal)

Http://www.cnr.it/ontology/cnr/pubblicazioni.owl#doi

• 10.1016/j.susc.2008.10.050 (literal)

Alternative label

• Piccinin, Simone; Stampfl, Catherine; Scheffler, Matthias (2009)
  Ag-Cu alloy surfaces in an oxidizing environment: a first-principles study
  in Surface science
  (literal)

Http://www.cnr.it/ontology/cnr/pubblicazioni.owl#autori

• Piccinin, Simone; Stampfl, Catherine; Scheffler, Matthias (literal)

Pagina inizio

• 1467 (literal)

Pagina fine

• 1475 (literal)

Http://www.cnr.it/ontology/cnr/pubblicazioni.owl#numeroVolume

• 603 (literal)

Rivista

• Surface science (Rivista)

Note

• ISI Web of Science (WOS) (literal)

Http://www.cnr.it/ontology/cnr/pubblicazioni.owl#affiliazioni

• School of Physics, The University of Sydney, New South Wales 2006, Sydney, Australia; Fritz-Haber-Institut der Max-Planck-Gesellschaft, Faradayweg 4-6, D-14195 Berlin, Germany (literal)

Titolo

• Ag-Cu alloy surfaces in an oxidizing environment: a first-principles study (literal)

Abstract

• Recent experiments on model catalysts have shown that Ag-Cu alloys have improved selectivity with respect to pure silver for ethylene epoxidation. In this paper, we review our first-principles investigations on the (11 1) surface of this alloy and present new findings on other low index surfaces. We find that, for every surface orientation, the presence of oxygen leads to copper segregation to the surface. Considering the alloy to be in equilibrium with an oxygen atmosphere and accounting for the effect of temperature and pressure, we compute the surface free energy and study the stability of several surface structures. Investigating the dependence of the surface free energy on the surface composition, we construct the phase diagram of the alloy for every surface orientation. Around the temperature, pressure and composition of interest for practical applications, we find that a limited number of structures can be present, including a thin layer of copper oxide on top of the silver surface and copper-free structures. Different surface orientations show a very similar behavior and in particular a single layer with CuO stoichiometry, significantly distorted when compared to a layer of bulk CuO, has a wide range of stability for all orientations. Our results are consistent with, and help explain, recent experimental measurements. (literal)

Prodotto di

• MD.P06.025.001 Teoria, simulazione e progetto assistito dal calcolatore di materiali nanostrutturati (MD.P06.025.002) (Modulo)

Autore CNR

• SIMONE PICCININ (Unità di personale interno)

Incoming links:

Autore CNR di

• SIMONE PICCININ (Unità di personale interno)

Prodotto

• MD.P06.025.001 Teoria, simulazione e progetto assistito dal calcolatore di materiali nanostrutturati (MD.P06.025.002) (Modulo)

Http://www.cnr.it/ontology/cnr/pubblicazioni.owl#rivistaDi

• Surface science (Rivista)