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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Influence of ceria and nickel addition to alumina-supported Rh catalyst for propane steam reforming at low temperatures
TL;DR: In this paper, the influence of ceria and nickel addition to alumina-supported Rh catalyst for steam reforming of propane at low temperatures has been studied by preparing and examining 2.
Journal ArticleDOI
C2-C5+ olefin production from CO2 hydrogenation using ceria modified Fe/Mn/K catalysts
TL;DR: In this paper, a formulated bifunctional catalyst that combines reverse water-gas-shift (RWGS) and Fischer-Tropsch chain growth activity was used for CO2 conversion to value-added hydrocarbons.
Journal ArticleDOI
In situ DRIFTS investigation of NH 3 -SCR reaction over CeO 2 /zirconium phosphate catalyst
Qiulin Zhang,Jie Fan,Ping Ning,Zhongxian Song,Xin Liu,Lanying Wang,Jing Wang,Huimin Wang,Kaixian Long +8 more
TL;DR: In this paper, a series of ceria modified zirconium phosphate catalysts were synthesized for selective catalytic reduction of NO with ammonia (NH 3 -SCR), and in situ DRIFTS results indicated that the NH 3-SCR reaction over the catalysts followed both Eley-Rideal and Langmuir-Hinshelwood mechanisms.
Journal ArticleDOI
Promotion effect of residual K on the decomposition of N2O over cobalt–cerium mixed oxide catalyst
TL;DR: A series of cobalt-cerium mixed oxide catalysts (CO3O4-CeO2) with a Ce/Co molar ratio of 0.05 were prepared by co-precipitation (with K2CO3 and KOH as the respective precipitant), impregnation, citrate, and direct evaporation methods and then tested for the catalytic decomposition of N2O as mentioned in this paper.
Journal ArticleDOI
Structure and surface properties of ceria-modified Ni-based catalysts for hydrogen production
Sonia Damyanova,Bárbara Pawelec,R. Palcheva,Yordanka Karakirova,M.C. Capel Sanchez,Georgi Tyuliev,Eric M. Gaigneaux,J.L.G. Fierro +7 more
TL;DR: In this paper, a series of Ni catalysts supported on alumina and mixed xCeO2-Al2O3 oxides with different CeO2 content were prepared by impregnation method by using different techniques such as: adsorption-desorption isotherms, XRD, UV-vis DRS, XPS, Raman, H2-TPR, EPR, TPO and TEM.
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.