Formation and Structural Properties of Ce−Zr Mixed Oxide Nanotubes

Abstract

In this work, ZrO2−CeO2 mixed oxide nanotubes with 50, 70, and 90 mol % CeO2 were synthesized following a very simple, high yield procedure, and their properties were characterized by synchrotron radiation XRD and by high resolution electron microscopy. The 50, 70, and 90 mol % CeO2 nanotubes exhibited the tetragonal phase (t′-form and t′′-form, P42/nmc space group) or the cubic phase (Fm3m space group). The nanotube walls were composed of nanoparticles with an average crystallite size ranging from 4.7 to 7.6 nm. Electron microscopy observations confirmed the size of these nanoparticles by direct observation. The SEM and TEM results showed that individual nanotubes were composed of a curved sheet of these nanoparticles. By SEM analysis, the nanotubes were found to have lengths of around 1−8 μm, diameters of around 500 nm, and wall thicknesses of 20 nm. Elemental analysis showed that Ce:Zr ratios appeared to be constant across space, suggesting compositional homogeneity in the samples. The 90 mol % CeO2 nanotubes exhibited the highest value of specific surface area, 101 m2·g−1, which compared with about 28 m2·g−1 for the other two compositions.

Nanotubes of rare earth cobalt oxides for cathodes of intermediate-temperature solid oxide fuel cells

“…In this sense, we are currently working on the use of Ba 0.5 Sr 0.5 Co 0.8 Fe 0.2 O 3 nanotubes and other cobaltites as IT-SOFC cathode, and on their use in anode materials and catalysts [25].…”

Low-temperature oxidation of ethanol over a Mn0.6Ce0.4O2 mixed oxide

“…The selected area electron diffraction (SAED) pattern (Fig. 2a) indicates that the sample consisted of very small crystallites, and was indexed to the cubic fluorite phase of ceria based on the interplanar spacing of 0.31 nm [15,16]. HRTEM images further indicated that these particles preferentially exposed the {1 1 1} crystal plane of ceria.…”

Ultra-simple synthetic approach to the fabrication of CeO2–ZrO2 mixed nanoparticles into homogeneous, domain, and core–shell structures in mesoporous spherical morphologies using supercritical alcohols

“…As a practical approach for minimizing Ce loading on nanomaterials, CeO 2 -ZrO 2 nanocomposites can be used as a substitute because of their chemical, mechanical, and thermal stability. Also, some of CeO 2 -ZrO 2 mixed oxides have been reported to show better catalytic performance compared to CeO 2 itself [9]. In order to achieve high performance, controlling the composition, topology, and morphology of CeO 2 -ZrO 2 composites at the nano level is very important.…”