Publication
Title
Local environment of Fe dopants in nanoscale Fe : oxygen storage material
Author
Abstract
Nanoscale Fe : CeO2-x oxygen storage material for the process of chemical looping has been investigated by advanced transmission electron microscopy and electron energy-loss spectroscopy before and after a model looping procedure, consisting of redox cycles at heightened temperature. Separately, the activity of the nanomaterial has been tested in a toluene total oxidation reaction. The results show that the material consists of ceria nanoparticles, doped with single Fe atoms and small FeOx clusters. The iron ion is partially present as Fe3+ in a solid solution within the ceria lattice. Furthermore, enrichment of reduced Fe2+ species is observed in nanovoids present in the ceria nanoparticles, as well as at the ceria surface. After chemical looping, agglomeration occurs and reduced nanoclusters appear at ceria grain boundaries formed by sintering. These clusters originate from surface Fe2+ aggregation, and from bulk Fe3+, which "leaks out" in reduced state after cycling to a slightly more agglomerated form. The activity of Fe : CeO2 during the toluene total oxidation part of the chemical looping cycle is ensured by the dopant Fe in the Fe1-xCexO2 solid solution, and by surface Fe species. These measurements on a model Fe : CeO2-x oxygen storage material give a unique insight into the behavior of dopants within a nanosized ceria host, and allow to interpret a plethora of (doped) cerium oxide-based reactions.
Language
English
Source (journal)
Nanoscale / Royal Society of Chemistry [London] - Cambridge
Publication
Cambridge : 2015
ISSN
2040-3364
Volume/pages
7:7(2015), p. 3196-3204
ISI
000349473200046
Full text (Publisher's DOI)
UAntwerpen
Faculty/Department
Research group
Project info
Counting Atoms in Nanomaterials (COUNTATOMS).
Revealing the source of emergent properties in complex oxides via direct imaging of charge/orbital/spin ordering.
Modified iron oxide materials for hydrogen production studied by operando XAS and TEM.
Publication type
Subject
Affiliation
Publications with a UAntwerp address
External links
Web of Science
Record
Identification
Creation 08.05.2015
Last edited 10.12.2017
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