title: Single-step process to prepare CeO2 nanotubes with improved catalytic activity.
abstract: CeO(2) nanotubes have been grown electrochemically using a porous alumina membrane as a template. The resulting material has been characterized by means of scanning electron microscopy (SEM), X-ray energy dispersive spectroscopy, high-angle annular dark-field scanning transmission electron microscopy tomography, high-resolution electron microscopy (HREM), and electron energy loss spectroscopy. According to SEM, the outer diameter of the nanotubes corresponds to the pore size (200 nm) of the alumina membrane, and their length ranges between 30 and 40 microm. HREM images have revealed that the width of the nanotube walls is about 6 nm. The catalytic activity of these novel materials for the CO oxidation reaction is compared to that of a polycrystalline powder CeO(2) sample prepared by a conventional route. The activity of the CeO(2) nanotubes is shown to be in the order of 400 times higher per gram of oxide at 200 degrees C (77.2 x 10(-2) cm(3) CO(2) (STP)/(gxs) for the nanotube-shaped CeO(2) and 0.16 x 10(-2) cm(3) CO(2) (STP)/(gxs) for the powder CeO(2)).
authors.affiliation: Department of Materials Science and Metallurgical Engineering and Inorganic Chemistry, University of Cadiz, Puerto Real, Cadiz, Spain.
authors.forename: Leandro
authors.initials: L
authors.lastname: González-Rovira
authors.forename: José M
authors.initials: JM
authors.lastname: Sánchez-Amaya
authors.forename: Miguel
authors.initials: M
authors.lastname: López-Haro
authors.forename: Eloy
authors.initials: E
authors.lastname: del Rio
authors.forename: Ana B
authors.initials: AB
authors.lastname: Hungría
authors.forename: Paul
authors.initials: P
authors.lastname: Midgley
authors.forename: José J
authors.initials: JJ
authors.lastname: Calvino
authors.forename: Serafín
authors.initials: S
authors.lastname: Bernal
authors.forename: F Javier
authors.initials: FJ
authors.lastname: Botana