Traditional analysis of reactions catalyzed by supported metals involves the structure of the metallic particles. However, we report here that for the class of nanostructured gold- or platinum-cerium oxide catalysts, which are active for the water-gas shift reaction, metal nanoparticles do not participate in the reaction. Nonmetallic gold or platinum species strongly associated with surface cer...

Cerium and its technologically relevant compounds are examples of anomalous mixed valency, originating from two competing oxidation states—itinerant Ce4+ and localized Ce3+. Under applied stress, anomalous transitions are observed but not well understood. Here we treat mixed valency as an “alloy” problem involving two valences with competing and numerous site-occupancy configurations. We use de...

In the context of the dynamical mean-field theory (DMFT) of the Hubbard model, we study the behavior of the compressibility near the density driven Mott transition at finite temperatures. We demonstrate this divergence using DMFT and quantum Monte Carlo simulations in the one-band and the two-band Hubbard model. We supplement this result with considerations based on the Landau theory framework,...

The dehalogenation of a-haloketones and a-halocarbonyl compounds is an inevitable proce­ dure for the organic synthesis and these reductive dehalogenations have been often effected in organic syntheses. There have been various procedures for the purpose and these are obtained by zinc and acetic acid [1], sodium dithionite [2], titanium(III) chloride [3], organotin hydride [4], sodium hydrogen t...

Compounds based on cerium are highly promising objects in biotechnology regarding their high biological activities such as antiviral, antibacterial, antifungal, neuro- and radioprotective action, antioxidant activity. On basis is possible to develop compositions capable of activating the systems cellular humoral immune defence use them for prevention therapy viral diseases, which makes it achie...

An iron(II) solution is often used as a reducing agent in titrimetry and standardized with cerium(IV) or potassium dichromate. Such an iron(II) standard solution is needed for not only titrimetric analyses, but also instrumental ones. Iron(II) is unstable even in a highly acidic solution, mainly due to air-oxidation; therefore, its standardization is required before use. In the present study...

J. G. He, Y. Li, X. X. Xue, H. Q. Ru, H. Yang School of Material and Metallurgy, Northeastern University, Shenyang, Liaoning, China. X. W. Huang National Engineering Research Center for Rare Earth Materials, General Research Institute for Nonferrous Metals, and Grirem Advanced Materials Co., Ltd., Beijing, China In this paper the removal of fl uoride from fl uoride-bearing cerium sulfate soluti...

A complex of cerium(III) with 4-methyl-7-hydroxycoumarin was synthesized by mixing water solutions of cerium(III) nitrate and 4-methyl-7-hydroxycoumarin sodium salt in a metal-to-ligand molar ratio of 1:2. The complex was characterized and identified by elemental analysis, conductometry, IR, 1H and 13C NMR-spectroscopy, mass spectral data, DTA and TGA. Thermal analysis of the complex indicated ...

cerium oxide (ceria) nano particle, as photodegradation prevention agent was studied in water-based polyurethane clear coat  systems. polyurethane coatings show superior weathering resistance compared with acrylic melamine systems. however, any chemical change has detrimental effects on the property profile of pu coatings. coatings containing various amounts of cerium oxide nanoparticles were p...