Publication
Title
Deactivation study of during redox cycles for CO production from
Author
Abstract
Deactivation was investigated in Fe2O3-CeO2 oxygen storage materials during repeated H-2-reduction and CO2-reoxidation. In situ XRD, XAS, and TEM were used to identify phases, crystallite sizes, and morphological changes upon cycling operation. The effect of redox cycling was investigated both in Fe-rich (80 wt % Fe2O3-CeO2) and Ce-rich (10 wt %Fe2O3-CeO2) materials. The former consisted of 100 nm Fe2O3 particles decorated with 5-10 nm Ce1-xFexO2-x. The latter presented CeO2 with incorporated Fe, i.e. a solid solution of Ce1-xFexO2-x, as the main oxygen carrier. By modeling the EXAFS Ce-K signal for as-prepared 10 wt %Fe2O3-CeO2, the amount of Fe in CeO2 was determined as 21 mol %, corresponding to 86% of the total iron content. Sintering and solid solid transformations, the latter including both new phase formation and element segregation, were identified as deactivation pathways upon redox cycling. In Ce-rich material, perovskite (CeFeO3) was identified by XRD. This phase remained inert during reduction and reoxidation, resulting in an overall lower oxygen storage capacity. Further, Fe segregated from the solid solution, thereby decreasing its reducibility. In addition, an increase in crystallite size occurred for all phases. In Fe-rich material, sintering is the main deactivation pathway, although Fe segregation from the solid solution and perovskite formation cannot be excluded.
Language
English
Source (journal)
Industrial and engineering chemistry research. - Washington, D.C., 1987, currens
Publication
Washington, D.C. : 2016
ISSN
0888-5885 [print]
1520-5045 [online]
Volume/pages
55:20(2016), p. 5911-5922
ISI
000376825300013
Full text (Publisher's DOI)
Full text (open access)
UAntwerpen
Faculty/Department
Research group
[E?say:metaLocaldata.cgzprojectinf]
Modified iron oxide materials for hydrogen production studied by operando XAS and TEM.
Publication type
Affiliation
Publications with a UAntwerp address
External links
Web of Science
Record
Identification
Creation 05.07.2016
Last edited 12.09.2017
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