Jump to main content
Jump to site search

Issue 43, 2017
Previous Article Next Article

Chemical surface exchange of oxygen on CeO2−δ in an O2/H2O atmosphere

Author affiliations

Abstract

The chemical surface reaction rate constant controlling the change of oxidation state of undoped ceria, kChem, was measured at 1400 °C in the range of (∼0 ≤ (pH2O/atm) ≤ 0.163(9)) and (10−3.85 ≤ (pO2/atm) ≤ 10−2.86) via the electrical conductivity relaxation method. In humidified atmospheres, kChem is fully described as the sum of kChem,O2 and kChem,H2O, which are, respectively, the rate constants for oxidation by O2 and by H2O alone. Using measurements under appropriately controlled gas conditions, the total rate constant is found to follow the correlation kChem/cm s−1 = 10−(1.35±0.07) × (pO2/atm)0.72±0.02 + 10−(3.85±0.03) × (pH2O/atm)0.36±0.03 where the pO2 and pH2O values of relevance are explicitly those of the final gas condition. The results suggest that at such high temperatures, the concentrations of surface adsorbed species are too low to influence the independent reaction pathways.

Graphical abstract: Chemical surface exchange of oxygen on CeO2−δ in an O2/H2O atmosphere

Back to tab navigation

Supplementary files

Publication details

The article was received on 01 Sep 2017, accepted on 09 Oct 2017 and first published on 09 Oct 2017


Article type: Paper
DOI: 10.1039/C7CP05969H
Citation: Phys. Chem. Chem. Phys., 2017,19, 29287-29293
  •   Request permissions

    Chemical surface exchange of oxygen on CeO2−δ in an O2/H2O atmosphere

    H. Ji, X. Xu and S. M. Haile, Phys. Chem. Chem. Phys., 2017, 19, 29287
    DOI: 10.1039/C7CP05969H

Search articles by author

Spotlight

Advertisements