A mechanism of CO oxidation by a thin surface oxide of Rh supported on ceria is proposed: CO is oxidized by the Rh-oxide film, which is subsequently reoxidized by a ceria surface O atom. The proposed mechanism is supported by in situ Raman spectroscopic investigations.

The objective of this study was to determine the residual pro-or anti-oxidant effects in rat brain 30 days after systemic administration of a 5 nm citrate-stabilized ceria dispersion. A ∼4% aqueous ceria dispersion was iv-infused (0 or 85 mg/kg) into rats which were terminated 30 days later. Ceria concentration, localization, and chemical speciation in the brain was assessed by inductively coup...

Model-type thin films of Gd doped and Gd/Mn co-doped ceria were investigated by means of impedance spectroscopy in a humid H2 atmosphere. A novel measurement technique for microelectrodes with interdigitating Pt current collectors was employed. This method allows a separation of the different elementary processes contributing to the electrode impedance. After annealing at 650°C in humid H2 atmo...

The microscopic mechanism behind the extraordinary ability of ceria to store, release, and transport oxygen is explained on the basis of first-principles quantum mechanical simulations. The oxygen-vacancy formation energy in ceria is calculated for different local environments. The reversible CeO2-Ce2O3 reduction transition associated with oxygen-vacancy formation and migration is shown to be d...

High surface area ceria nanoparticles have been prepared using a citrate sol-gel precipitation method. Changes to the particle size have been made by doping ceria powders, and calcining at different temperatures. Xray methods were used to determine their lattice parameters. The particle sizes have been assessed using transmission electron microscopy (TEM) and the lattice parameter found to fall...

The electrochemical properties of the metal | doped ceria | metal system have been examined by A.C. impedance spectroscopy at a range of temperatures (575–650 °C) and oxygen partial pressures (8×10–0.21 atm). Under reducing conditions, the inverse of the interfacial resistances for both Pt and Au electrodes on samarium-doped ceria (SDC) displayed a pO2 −1/4 dependence on oxygen partial pressure...

Pure and mixed lanthanum and cerium oxides were synthesized via a reverse microemulsion-templated route. This approach yields highly homogeneous and phase-stable mixed oxides with high surface areas across the entire range of La:Ce ratios from pure lanthana to pure ceria. Surprisingly, all mixed oxides show the fluorite crystal structure of ceria, even for 10 lanthanum contents as high as 90%. ...

The nano-domain, with short-range ordered structure, has been widely observed in rare-earth-doped ceria. Atomistic simulation has been employed to investigate the ordering structure of the nano-domain, as a result of aggregation and segregation of dopant cations and the associated oxygen vacancies in gadolinium-doped ceria. It is found that the binding energy of defect cluster increases as a fu...

The phases of ceria–zirconia nanoparticles observed in air are studied as a function of particle size and composition by X-ray diffraction, transmission electron microscopy, and Raman spectroscopy. The emergence of two tetragonal phases t00 and t monotonically moves toward higher zirconia concentrations with decreasing particle size. A smaller particle size increases the solubility of zirconia ...

We have studied the electronic states in three different ceria thin film surfaces prepared on a Cu(111) single-crystal surface by vapor deposition at different conditions: at 250 °C, at room temperature and finally Au-doped ceria film obtained by simultaneous deposition of Au and CeO2 at room temperature (RT). Electronic properties of the layers and interaction of gold with CeO2 were investigat...