Journal ArticleDOI
Characterization of ceria-coated alumina carrier
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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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Preparation and Characterization of Me2O3−CeO2 (Me = B, Al, Ga, In) Mixed-Oxide Catalysts
TL;DR: In this paper, the synthesis and characterization of ceria-based mixed oxides with a wide range of Me2O3 contents have been investigated by a coprecipitation route and the obtained solid materials have been characterized in terms of their structural, textural, and surface properties.
Journal ArticleDOI
Hydrogen production by auto-thermal reforming of ethanol over nickel catalysts supported on Ce-modified mesoporous zirconia: Effect of Ce/Zr molar ratio
Min Hye Youn,Jeong Gil Seo,Kyung Min Cho,Sunyoung Park,Dong Ryul Park,Ji Chul Jung,In Kyu Song +6 more
TL;DR: In this paper, the effect of Ce/Zr molar ratio (X) on the catalytic performance of 20% Ni catalysts supported by mesoporous zirconia (Zr-Ce-X) supports was investigated.
Journal ArticleDOI
The Influence of Alkali Metals on the Ce‐Ti Mixed Oxide Catalyst for the Selective Catalytic Reduction of NOx
TL;DR: In this paper, a combined experimental and theoretical study was used to reveal the mechanism of the deactivation caused be the alkali metals, which indicated that the doping of alkali metal atoms on the catalyst surface greatly decreases the surface acidity and reducibility.
Journal ArticleDOI
Preparation and property investigation of CeO2-ZrO2-Al2O3 oxygen-storage compounds
TL;DR: In this paper, a co-precipitation method was used for the co-storage of CeO2-ZrO2 and Al2O3 (CZA), with alumina contents 10, 25, 50, 75 and 90% respectively.
Journal ArticleDOI
Understanding the effect of Sm2O3 and CeO2 promoters on the structure and activity of Rh/Al2O3 catalysts in methane steam reforming
R. B. Duarte,R. B. Duarte,Maarten Nachtegaal,José Maria C. Bueno,J. A. van Bokhoven,J. A. van Bokhoven +5 more
TL;DR: In this article, the role of Sm 2 O 3 and CeO 2 promoters on the structural properties and catalytic behavior of Rh/Al 2O 3 catalysts during methane steam reforming (MSR) was investigated.
References
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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.