Investigation of CO 2 Splitting on Ceria-Based Redox Materials for Low-Temperature Solar Thermochemical Cycling with Oxygen Isotope Exchange Experiments.
In: Processes, Jg. 11 (2023), Heft 1, S. 109-124
academicJournal
Zugriff:
The surface exchange and bulk transport of oxygen are highly relevant to ceria-based redox materials, which are envisaged for the solar thermochemical splitting of carbon dioxide in the future. Experimental investigations of oxygen isotope exchange on CeO 2-δ , Ce 0.9 M 3+ 0.1 O 1.95-δ (with M 3+ = Y, Sm) and Ce 0.9 M 4+ 0.1 O 2-δ (with M 4+ = Zr) samples were carried out for the first time utilizing oxygen-isotope-enriched C 18 O 2 gas atmospheres as the tracer source, followed by Secondary Ion Mass Spectrometry (SIMS), at the temperature range 300 ≤ T ≤ 800 °C. The experimental K ˜ O and D ˜ O data reveal promising results in terms of CO 2 splitting when trivalent (especially Sm)-doped ceria is employed. The reaction temperatures are lower than previously proposed/reported due to the weak temperature dependency of the parameters K ˜ O and D ˜ O . The majority of isotope exchange experiments show higher values of K ˜ O and D ˜ O for Sm-doped cerium dioxide in comparison to Y-doped and Zr-doped ceria, as well as nominally undoped ceria. The apparent activation energies for both K ˜ O and D ˜ O are lowest for Sm-doped ceria. Using Zr-doped cerium oxide exhibits various negative aspects. The Zr-doping of ceria enhances the reducibility, but the possible Zr-based surface alteration effects and dopant-induced migration barrier enhancement in Zr-doped ceria are detrimental to surface exchange and oxygen diffusion at lower temperatures of T ≤ 800 °C. [ABSTRACT FROM AUTHOR]
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Titel: |
Investigation of CO 2 Splitting on Ceria-Based Redox Materials for Low-Temperature Solar Thermochemical Cycling with Oxygen Isotope Exchange Experiments.
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Autor/in / Beteiligte Person: | Uxa, Daniel ; Dörrer, Lars ; Schulz, Michal ; Knoblauch, Nicole ; Fielitz, Peter ; Roeb, Martin ; Schmücker, Martin ; Borchardt, Günter |
Zeitschrift: | Processes, Jg. 11 (2023), Heft 1, S. 109-124 |
Veröffentlichung: | 2023 |
Medientyp: | academicJournal |
ISSN: | 2227-9717 (print) |
DOI: | 10.3390/pr11010109 |
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