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Steiner, Carsten ; Kogut, Iuri ; Hagen, Gunter ; Fritze, Holger ; Moos, Ralf:
Investigation of the Defect-Chemistry of Ceria-Zirconia Mixed Oxides (CZO) Using Microwaves.
2021
Veranstaltung: PACRIM 14, The 14th Pacific Rim Conference of Ceramic Societies
, 13.12.-16.12.2021
, Vancouver (virtual), USA.
(Veranstaltungsbeitrag: Kongress/Konferenz/Symposium/Tagung
,
Vortrag
)
Abstract
Ceria-zirconia mixed oxides (CZO) are oxygen storage materials. They are an elementary part of three-way catalysts (TWC) in modern gasoline vehicles. Previous studies showed that the oxygen storage level of a TWC can be operando determined using microwave technology. To investigate the dielectric behavior of CZO under microwave conditions in more detail, Ce1-xZrxO2-δ powders were studied in a microwave resonator specifically designed for high temperatures in a wide oxygen partial pressure (pO2) range. Dielectric properties of the CZO powders were analyzed between pO2≈ 10-25 bar and pO2≈ 0.2 bar at 600 °C. Under oxidizing conditions, a lower pO2 led to an increase in conductivity, which is likely related to an activated small-polaron hopping mechanism due to oxygen vacancy formation. Under reducing conditions, only small changes in conductivity were observed, which is probably attributed to a suppression of the hopping mechanism by higher non-stoichiometries δ ([Ce3+] ≈ [Ce4+]). Additionally, comparison with data of pure ceria suggests that the formation of oxygen vacancies in CZO is hardly dependent on the microstructure. The results of the study provide further insight into CZO and may contribute to better understand the defect chemistry of CZO and to improve the control of three-way catalysts using microwave technology.
Weitere Angaben
| Publikationsform: | Veranstaltungsbeitrag (Vortrag) |
|---|---|
| Begutachteter Beitrag: | Ja |
| Institutionen der Universität: | Fakultäten > Fakultät für Ingenieurwissenschaften Fakultäten > Fakultät für Ingenieurwissenschaften > Lehrstuhl Funktionsmaterialien > Lehrstuhl Funktionsmaterialien - Univ.-Prof. Dr.-Ing. Ralf Moos Profilfelder > Advanced Fields > Neue Materialien Forschungseinrichtungen > Forschungszentren > Bayreuther Materialzentrum - BayMAT Fakultäten Fakultäten > Fakultät für Ingenieurwissenschaften > Lehrstuhl Funktionsmaterialien Profilfelder Profilfelder > Advanced Fields Forschungseinrichtungen Forschungseinrichtungen > Forschungszentren |
| Titel an der UBT entstanden: | Ja |
| Themengebiete aus DDC: | 600 Technik, Medizin, angewandte Wissenschaften > 620 Ingenieurwissenschaften |
| Eingestellt am: | 21 Dec 2021 08:32 |
| Letzte Änderung: | 21 Dec 2021 08:32 |
| URI: | https://eref.uni-bayreuth.de/id/eprint/68208 |