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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Journal ArticleDOI
Introduction manner of sulfate acid for improving the performance of SO42−/CeO2 on selective catalytic reduction of NO by NH3
TL;DR: In this paper, a series of sulfated CeO 2 catalysts were synthesized by impregnation and solgel methods and used for selective catalytic reduction (SCR) of NO x by NH 3.
Book ChapterDOI
Synthesis and properties of cerium oxide-based materials
TL;DR: Cerium dioxide (CeO2), also called ceria, is the most famous cerium compound, in the wake of its unmatched redox properties and the ability to guarantee an excellent oxygen mobility as discussed by the authors.
Journal ArticleDOI
K2O supported on sol-gel CeO2-Al2O3 and La2O3-Al2O3 catalysts for the transesterification reaction of canola oil
TL;DR: In this article, a heterogeneous supported potassium on promoted CeO2-Al2O3 and La2O 3-Al 2O3 sol-gel mixed oxides was used as a catalyst for biodiesel production via the transesterification of canola oil with methanol using a batch reactor.
Journal ArticleDOI
Self-assembling synthesis of α-Al2O3–carbon composites and a method to increase their photoluminescence
Shifa Wang,Shifa Wang,Chuanfei Zhang,Guangai Sun,Yonggang Yuan,Chen Liang,Xia Xiang,Qing-Ping Ding,Bo Chen,Zhijie Li,Xiaotao Zu +10 more
TL;DR: In this article, the results indicate that the sample morphology depends on the choice of chelating agent and that the carbon doping improved the luminescence properties of α-alumina and did not change the rhombohedral structure of the host.
Journal ArticleDOI
Ni/CaO-SiO2 catalysts for assessment in steam reforming reaction of acetol
TL;DR: In this paper, the Aqueous impregnation method obtained catalysts with different CaO contents (0, 20, 40, and 100wt%) as additive on Ni/SiO2.
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.