Studies On Synthesis, Microstructure and Transport Properties of Doped Cerium Oxides

atmire.migration.oldid3579
dc.contributor.advisorThangadurai, Venkataraman
dc.contributor.authorHandal, Hala
dc.date.accessioned2015-09-17T16:14:00Z
dc.date.available2015-11-20T08:00:39Z
dc.date.issued2015-09-17
dc.date.submitted2015en
dc.description.abstractAcceptor-doped ceria exhibits mixed ionic electronic conduction in reducing conditions and chemical stability against sulfur poisoning and coking. This thesis’s primary goal is to explore new anode materials based on ceria–solid solutions for solid oxide fuel cells (SOFCs). The physicochemical and electrochemical performance of Ce0.9–xY0.1MnxO2–δ (x = 0 to 15 mol%) (CYMO) and Ce0.87Y0.1Mn0.01N0.02O2-δ (N = Mg or Ca) were studied. Among the materials investigated in this study, Ce0.89Y0.1Mn0.01Mg0.02O2–δ (Mg-CYMO) showed the highest total conductivity of 0.2 S cm−1 at 700 °C in H2. An area specific polarization resistance of 0.23 Ω cm2 was observed for both Mg-CYMO and Ce0.8Y0.1Mn0.1O2-δ (10CYMO) at 800 °C, in wet H2. Chronoamperometric measurement for the symmetrical cell configuration based on 10CYMO electrodes showed stable performance upon exposure to 10 ppm H2S/H2. In a full cell configuration, 10CYMO (anode)/YSZ (electrolyte)/La0.8Sr0.2MnO3 (LSM)-YSZ cathode, polarization resistance of 1.4 Ω cm2 and power density of 75 mW/cm2 were obtained at 800 °C in wet H2. The main challenge of employing proton-conducting electrolytes in SOFC is their poor chemical stability in the presence of steam and hydrocarbon fuels. Another goal of this thesis is to develop a chemically stable proton-conducting electrolyte for SOFCs. The effects of Fe and Co substitution on the electrical and physicochemical properties of BaCe0.9Sm0.1O3–δ (BCS) were evaluated. Thermogravimetric analysis showed that incorporation of 5 to 10 mol% Fe or Co in BCS did not improve the chemical stability in CO2 at elevated temperatures. The BCSC10 sample sintering at 1400 °C showed the highest electrical conductivity of 0.02 S cm-1 at 600 °C in air, but it did not show any appreciable proton mobility under humidified atmosphere.en_US
dc.identifier.citationHandal, H. (2015). Studies On Synthesis, Microstructure and Transport Properties of Doped Cerium Oxides (Doctoral thesis, University of Calgary, Calgary, Canada). Retrieved from https://prism.ucalgary.ca. doi:10.11575/PRISM/27916en_US
dc.identifier.doihttp://dx.doi.org/10.11575/PRISM/27916
dc.identifier.urihttp://hdl.handle.net/11023/2461
dc.language.isoeng
dc.publisher.facultyGraduate Studies
dc.publisher.institutionUniversity of Calgaryen
dc.publisher.placeCalgaryen
dc.rightsUniversity of Calgary graduate students retain copyright ownership and moral rights for their thesis. You may use this material in any way that is permitted by the Copyright Act or through licensing that has been assigned to the document. For uses that are not allowable under copyright legislation or licensing, you are required to seek permission.
dc.subjectEnergy
dc.subjectMaterials Science
dc.subject.classificationPhysical scienceen_US
dc.subject.classificationMaterials Scienceen_US
dc.subject.classificationEnergyen_US
dc.titleStudies On Synthesis, Microstructure and Transport Properties of Doped Cerium Oxides
dc.typedoctoral thesis
thesis.degree.disciplineChemistry
thesis.degree.grantorUniversity of Calgary
thesis.degree.nameDoctor of Philosophy (PhD)
ucalgary.item.requestcopytrue
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