Doped Cerium Oxide

The addition of cerium oxide, for example, to zirconia produces a material with exceptional toughness and good strength [29], Cerium oxide-doped zirconia is used also in thermal barrier spray coatings on metal surfaces(30]. 

Sulfur oxides and nitrogen oxides may be removed from combustion gases by various processes. One of the cost-effective and efficient methods involve dry scrubbing of SOx and NOx over lanthanide-oxygen-sulfur compounds (Jalan and Desai 1992). Cerium sulfate is found to be an effective catalyst toward the reduction of NOx by ammonia. A combined removal of NOx and SOx has been achieved using cerium oxide doped with strontium oxide, lanthanum oxide, calcium oxide, or cerium sulfate. 

Hatch well CE, Sammes NM, Tompsett GA, and Brown IWM. Chemical compatibility of chromium-based interconnect related materials with doped cerium oxide electrolyte. J. Eur. Ceram. Soc. 1999 19 1697-1703. 

Catalyst systems for the WGS reaction that have recently received significant attention are the cerium oxides, mostly loaded with noble metals, especially platinum 42—46]. Jacobs et al. [44] even claim that it is probable that promoted ceria catalysts with the right development should realize higher CO conversions than the commercial Cu0-Zn0-Al203 catalysts. Ceria doped with transition metals such as Ni, Cu, Fe, and Co are also very interesting catalysts 37,43—471, especially the copper-ceria catalysts that have been found to perform excellently in the WGS reaction, as reported by Li et al. [37], They have found that the copper-ceria catalysts are more stable than other Cu-based LT WGS catalysts and at least as active as the precious metal-ceria catalysts. 

Transparency to the incident radiation is a trait of a transducer. Yttrium oxide, doped with lanthanum oxide is transparent to IR radiation. Blocking of undesired UV radiation is achieved by cerium doped glasses. Some examples of modulating transducers are given in Table 12.17. 

Pale yellow cerium dioxide (ceria, ceric oxide) has the fluorite structure and is used in catalysis" ", solid oxide fuel cells (SOFC)", thin film optical waveguides" , reversible oxygen storage materials for automobile catalysts" and for doping copper oxide superconductors". The diverse cerium enolate precursors and deposition methods used in the formation of cerium oxide thin films are summarized in Table 6, whereby the most common precursor for ceria is Ce(thd)4. 

Yttria-doped( 20 mol% Y2O3) cerium oxide also has a higher 0 ion conductivity than yttria-stabilized zirconia ( factors of 11-18 at 600°C), which would make it an attractive choice for an electrolyte at lower temperatures (< 800 C) However, doped cerium oxides tend to undergo reduction, with formation of trivalent cerium ions and oxygen ion vacancies, V 6 leading to the onset of electronic conductivity according to ... 

The interpretation of the spectral details was improved by comparing results from two model calculations, one for an undoped cerium oxide lattice and the other for a Sc doped lattice. The main hydrogen site was found to be at the Ce, giving features about 650 cm. The minority population was next to the doped site, giving features about 850 cm [63]. The temperature dependence of the y(OH...O), 805 cm, in RbHS04 was also measured. 

Key words Solid Oxygen-Conduction Electrolyte/Doped Cerium Oxide/Nanopowders... 

Gallate/Samarium Doped Cerium Oxide/Strontium Iron Cohaltite... 

Cerium oxide, ceria, has a fluorite structure and shows oxide anion conducting behavior differ from other rare earth oxides. However, the O ionic conductivity of pure ceria is low because of a lack of oxide anion vacancies. For ion conduction, especially for anion, it is important to have such an enough vacancy in the crystal lattice for ion conduction. Therefore, the substitution of tetravalent Ce" by a lower valent cation is applied in order to introduce the anion vacancies. For the dopant cation, divalent alkaline earth metal ions and some rare earth ions which stably hold trivalent state are usually selected. Figure 9-28 shows the dopant ionic radius dependencies of the oxide ionic conductivity for the doped ceria at 800°C. In the case of rare earth doped Ce02, the highest O ion conductivity was obtained for... 

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