Journal ArticleDOI
Characterization of ceria-coated alumina carrier
TLDR
In this paper, it was shown that different types of cerium oxide species are formed on the surface depending on the amount of CeO2 and temperature of calcination of the samples.Abstract:
CeO2–Al2O3 mixed oxides with different CeO2 loading (in the range of 0.5–12 wt.%) were prepared by wetness impregnation of alumina with aqueous solution of di-ammonium hexanitrate cerate (NH4)2[Ce(NO3)6]. The samples after calcination at 773 and 1073 K were characterized by different techniques, using X-ray diffraction (XRD), UV–VIS diffuse reflectance spectroscopy (DRS), X-ray photoelectron spectroscopy (XPS) and temperature-programmed reduction (TPR). It is shown that different types of cerium oxide species are formed on the surface depending on the amount of CeO2 and temperature of calcination of the samples. XRD showed the formation of nanocrystallites of ceria on alumina surface when the amount of CeO2 is higher than 6 wt.%; at lower concentrations ceria was found to be amorphous. The ceria loading lower than 6 wt.% stabilizes the textural properties of alumina. At loading of 1 wt.% of CeO2 XPS spectra reveals the presence of a strong interaction between ceria and alumina leading to a formation of superficial CeAlO3-like phase. TPR results show that well dispersed CeO2 particles present on the surface of alumina form CeAlO3 at temperature of reduction in the range of 873–993 K, while for the reduction of CeO2 crystallites, a higher temperature of reduction of 1190 K is needed.read more
Citations
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Patent
Alumina supported type cerium oxide powder material preparation method
TL;DR: In this article, an alumina supported type cerium oxide powder material preparation method is described, which comprises: chemical vapor deposition method is adopted, a cerium metal organic precursor is effectively decomposed in an oxygen atmosphere and in a temperature range of 500-700 DEG C, and CeO nano particles are generated and uniformly dispersed on the support alumina.
Dissertation
Avaliação de catalisadores de Cu e K2O suportados em CeO2 e Nb2O5 utilizados em reações de reforma a vapor do metanol para a obtenção de hidrogênio
TL;DR: In this article, a reacao de reforma a vapor do metanol and a processo importante de geracao of hidrogenio, which vem sendo muito utilizado na industria, was investigated.
Journal ArticleDOI
Ceria Zirconia Mixed Oxides Prepared by Hydrothermal Templating Method for the Oxidation of Ethyl Benzene
Cimi A Daniel,Sankaran Sugunan +1 more
TL;DR: Daniel et al. as mentioned in this paper used a surfactant-templated method using cetyl trimethyl ammonium bromide (CTAB) as template for the preparation of CeO2-ZrO2 oxides.
Journal ArticleDOI
Preparation and characterization of yttria–ceria doped tetragonal zirconia / alumina composites
TL;DR: In this paper, Yttria-ceria doped tetragonal zirconia / alumina, (Y,Ce-TZP / Al2O3) composites were prepared via sol-gel and powder mixing techniques.
References
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Journal ArticleDOI
Revised effective ionic radii and systematic studies of interatomic distances in halides and chalcogenides
TL;DR: The effective ionic radii of Shannon & Prewitt [Acta Cryst. (1969), B25, 925-945] are revised to include more unusual oxidation states and coordinations as mentioned in this paper.
Journal ArticleDOI
High-Resolution X-Ray Photoemission Spectrum of the Valence Bands of Gold
TL;DR: In this paper, high-resolution gold-valence-band photoemission spectra were obtained by the use of monochromatized k-ensuremath-alpha (kα) radiation and a single-crystal specimen.
Journal ArticleDOI
Catalytic Properties of Ceria and CeO2-Containing Materials
TL;DR: A survey of the use of cerium oxide and CeO2-containing materials as oxidation and reduction catalysts is presented in this paper, with a special focus on catalytic interaction with small molecules such as hydrogen, carbon monoxide, oxygen, and nitric oxide.
Journal ArticleDOI
Ceria in automotive exhaust catalysts: I. Oxygen storage
H.C. Yao,Y.F. Yu Yao +1 more
TL;DR: In this article, the authors measured the oxygen removal at various temperatures using TPR traces of unsupported or alumina-supported ceria and showed that the reduction of surface capping oxygen and bulk oxygen anions is associated with reduction of the shared oxygen anion at the interface.
Book
X-Ray Diffraction in Crystals, Imperfect Crystals, and Amorphous Bodies
TL;DR: In the formalism of Newman-Penrose, a family of exact solutions of the Einsteirr-Maxwell equations of the type of Bertotti-Robinson is obtained with a cosmological term belonging to the degenerate type D in the algebraic classification of Petrov.