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
High carbon-resistance Ni/CeAlO3-Al2O3 catalyst for CH4/CO2 reforming
TL;DR: In this article, high carbon-resistance Ni/Ce-AlO catalysts have been developed for dry reforming of methane (DRM) that is attracting growing attention for chemical recycling of CO2 to fuels/chemicals.
Journal ArticleDOI
Glycerol steam reforming over Ni catalysts supported on ceria and ceria-promoted alumina
A. Iriondo,V.L. Barrio,Jose F. Cambra,Pedro L. Arias,M.B. Güemez,Maricruz Sanchez-Sanchez,Rufino M. Navarro,José Luis García Fierro +7 more
TL;DR: In this article, the catalytic performance of glycerol steam reforming over Ni catalysts supported on bare CeO 2 and Al 2 O 3, and with the addition of low ceria loadings enhances the activity of the NiAl catalyst.
Journal ArticleDOI
Knoevenagel condensation reaction over acid-base bifunctional nanocrystalline CexZr1-xO2 solid solutions
TL;DR: In this paper, high-temperature stable three-dimensional spongelike mesoporous Ce x Zr 1− x O 2 solid solutions consisting of nanometer size particles with different Ce/Zr compositions were synthesized by a modified sol-gel procedure using a triethanolamine/water mixture as a solvent to be used in liquid Knoevenagel condensation reaction.
Journal ArticleDOI
CO2 hydrogenation into CH4 on NiHNaUSY zeolites
Inês Graça,L. V. González,M.C. Bacariza,Auguste Fernandes,Carlos Henriques,José Manuel Lopes,Maria Filipa Ribeiro +6 more
TL;DR: In this paper, a CO2 hydrogenation into methane was carried out over catalysts containing nickel and cerium species supported on a HNaUSY zeolite, using an H2/CO2 ratio of 4 and temperatures ranging from 250 to 450°C.
Journal ArticleDOI
Investigation of palladium interaction with cerium oxide and its state in catalysts for low-temperature CO oxidation
Andrei I. Boronin,Elena M. Slavinskaya,I. G. Danilova,R.V. Gulyaev,Yu. I. Amosov,P. A. Kuznetsov,I. A. Polukhina,S.V. Koscheev,Vladimir I. Zaikovskii,A. S. Noskov +9 more
TL;DR: In this paper, the structure of the active sites consisting of two phases: atomically dispersed palladium within the SIP and palladium metal nanoclusters is proposed, which correspond to the surface interaction phases (SIPs) as PdxCeO2−δ and small metal clusters.
References
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Journal ArticleDOI
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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.
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High-Resolution X-Ray Photoemission Spectrum of the Valence Bands of Gold
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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.