Affordable Access

deepdyve-link
Publisher Website

Thermal stability of doped ceria: experiment and modelling

Authors
  • Pijolat, Michèle
  • Prin, Marie-Agnès
  • Soustelle, Michel
  • Touret, Olivier
  • Nortier, Patrice
Publication Date
Jan 01, 1995
Identifiers
DOI: 10.1039/FT9959103941
OAI: oai:HAL:emse-00610336v1
Source
HAL-Descartes
Keywords
Language
English
License
Unknown
External links

Abstract

The process of the decrease of the surface area due to crystallite growth in ceria at 943 K is described by a kinetic model involving oxygen and cerium diffusion. The experimentally found variations in the rate of crystallite growth are reported as a function of the content ( 10% cat.) of dopants, which are the cations Ca<sup>2+</sup>, Mg<sup>2+</sup>, Al<sup>3+</sup>, Y<sup>3+</sup>, Sc<sup>3+</sup>, Al<sup>3+</sup>, Th<sup>4+</sup>, Zr<sup>4+</sup> and Si<sup>4+</sup>. The variations are discussed on the basis of the diffusion of cerium vacancies as the rate-limiting step, and on the basis of calculated expressions of the concentrations of oxygen vacancies, electrons and cerium vacancies v<sub>s</sub>. the oxygen partial pressure and the dopant content. For cations that are smaller than Ce<sup>4+</sup>, the comparison between the experimental and theoretical rates asserts the validity of the model and allows the prediction of the efficiency of a cation to stabilize the surface area, from its associations with oxygen vacancies and with the electron-bearing species, Ce′<sub>Ce</sub>.

Report this publication

Statistics

Seen <100 times