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Chemical surface exchange of oxygen on CeO_(2−δ) in an O_2/H_2O atmosphere

Ji, Ho-Il and Xu, Xin and Haile, Sossina M. (2017) Chemical surface exchange of oxygen on CeO_(2−δ) in an O_2/H_2O atmosphere. Physical Chemistry Chemical Physics, 19 (43). pp. 29287-29293. ISSN 1463-9076. https://resolver.caltech.edu/CaltechAUTHORS:20171026-135406928

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Abstract

The chemical surface reaction rate constant controlling the change of oxidation state of undoped ceria, k_(Chem), was measured at 1400 °C in the range of (∼0 ≤ (pH_2O/atm) ≤ 0.163(9)) and (10^(−3.85) ≤ (pO_2/atm) ≤ 10^(−2.86)) via the electrical conductivity relaxation method. In humidified atmospheres, k_(Chem) is fully described as the sum of k_(Chem,O2) and k_(Chem,H2)O, which are, respectively, the rate constants for oxidation by O_2 and by H_2O alone. Using measurements under appropriately controlled gas conditions, the total rate constant is found to follow the correlation k_(Chem)/cm s^(−1) = 10^(−(1.35±0.07)) × (pO_2/atm)^(0.72±0.02) + 10^(−(3.85±0.03)) × (pH_2O/atm)^(0.36±0.03) where the pO_2 and pH_2O 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.


Item Type:Article
Related URLs:
URLURL TypeDescription
https://doi.org/10.1039/c7cp05969hDOIArticle
http://pubs.rsc.org/en/Content/ArticleLanding/2017/CP/C7CP05969HPublisherArticle
http://www.rsc.org/suppdata/c7/cp/c7cp05969h/c7cp05969h1.pdfPublisherSupplemental Information
ORCID:
AuthorORCID
Ji, Ho-Il0000-0002-6194-991X
Haile, Sossina M.0000-0002-5293-6252
Additional Information:© 2017 the Owner Societies. Received 1st September 2017, Accepted 9th October 2017, First published on 9th October 2017. This material is based upon work supported by the U.S. Department of Energy, through ARPA-e Contract DE-AR0000182. There are no conflicts to declare.
Funders:
Funding AgencyGrant Number
ARPA-EDE-AR0000182
Issue or Number:43
Record Number:CaltechAUTHORS:20171026-135406928
Persistent URL:https://resolver.caltech.edu/CaltechAUTHORS:20171026-135406928
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:82704
Collection:CaltechAUTHORS
Deposited By: Tony Diaz
Deposited On:26 Oct 2017 21:29
Last Modified:03 Oct 2019 18:57

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