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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Catalytic Ozonation by Manganese, Iron and Cerium Oxides on γ-Al2O3 Pellets for the Degradation of Organic Pollutants in Continuous Fixed-Bed Reactor
Abstract: Heterogeneous catalytic ozonation is an efficient technology for degrading refractory organic pollutants in water. However, most studied heterogeneous catalysts for catalytic ozonation were powders...
Journal ArticleDOI
Thermally stable α-alumina supported ceria for coking resistance and oxidation of radical coke generated in-situ
Shilpa Mahamulkar,Kehua Yin,Micaela Taborga Claure,Robert J. Davis,Liwei Li,Hirokazu Shibata,Andrzej Malek,Christopher W. Jones,Pradeep K. Agrawal +8 more
TL;DR: In this paper, a series of thermally stable α-alumina supported and unsupported ceria catalysts with varying composition was systematically investigated under realistic coke-catalyst contact conditions for the oxidation of in-situ generated coke during ethylene pyrolysis.
Journal ArticleDOI
Effect of Mg/Al molar ratios on NO reduction activity of CO using Ce-La/MgAl 2 O 4 -x catalysts
TL;DR: In this article, a series of Ce-La/MgAl 2 O 4 -x catalysts were prepared by the incipient wetness impregnation method and characterized by BET, XRD, H 2 -TPR, CO-TPR and in situ FT-IR.
Journal ArticleDOI
Facile synthesis of monodispersed CeO2 nanostructures
TL;DR: CeO 2 polycrystalline structures with uniform diameters in the range of 10-20nm and lengths up to 80nm were successfully prepared by a facile and environmentally friendly mixed-solvothermal method under mild conditions.
Journal ArticleDOI
Waste-Reducing Catalytic Oxidation of m-Xylene to m-Toluic Acid
TL;DR: In this article, the performance of Co/Mn/Ce catalysts for m-xylene (MX) oxidation without acetic acid (HAc) solvent was compared with Co/HAc catalysts.
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.
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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.