A computer simulation study of the Ce4+/Ce3+ reduction process in CeO2-MO (M = Ca, Mn, Ni, Zn) and CeO 2-M2O3 (M = Sc, Mn, Y, Gd, La) mixed oxides is presented. Calculations satisfactorily reproduce the observed structural parameters of the solid solutions over a wide range of compositions. On energetic grounds, the Ce4+/Ce3+ reduction process is enhanced with increasing dopant content, with the enhancement being more pronounced for divalent dopants. For a fixed dopant level, the reduction of cerium is more favorable for larger dopant ions. The results are explained in terms of the higher oxygen vacancy concentration and the larger dopant size being effective in accommodating the greater relaxation or elastic strain associated with forming the larger Ce3+ species upon reduction.

Reduction process in CeO2-MO and CeO2-M2O3 mixed oxides: A computer simulation study

BALDUCCI, GABRIELE;KASPAR, JAN;FORNASIERO, Paolo;GRAZIANI, MAURO
2003

Abstract

A computer simulation study of the Ce4+/Ce3+ reduction process in CeO2-MO (M = Ca, Mn, Ni, Zn) and CeO 2-M2O3 (M = Sc, Mn, Y, Gd, La) mixed oxides is presented. Calculations satisfactorily reproduce the observed structural parameters of the solid solutions over a wide range of compositions. On energetic grounds, the Ce4+/Ce3+ reduction process is enhanced with increasing dopant content, with the enhancement being more pronounced for divalent dopants. For a fixed dopant level, the reduction of cerium is more favorable for larger dopant ions. The results are explained in terms of the higher oxygen vacancy concentration and the larger dopant size being effective in accommodating the greater relaxation or elastic strain associated with forming the larger Ce3+ species upon reduction.
File in questo prodotto:
Non ci sono file associati a questo prodotto.

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: http://hdl.handle.net/11368/1695736
 Attenzione

Attenzione! I dati visualizzati non sono stati sottoposti a validazione da parte dell'ateneo

Citazioni
  • ???jsp.display-item.citation.pmc??? ND
  • Scopus 78
  • ???jsp.display-item.citation.isi??? 80
social impact