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Title: Phases in ceria-zirconia binary oxide (1-x)CeO2-xZrO2 nanoparticles: the size effects

Abstract

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 t{prime}{prime} and t monotonically moves toward higher zirconia concentrations with decreasing particle size. A smaller particle size increases the solubility of zirconia in cubic ceria, while higher zirconia content in ceria stabilizes against coarsening. In particular, the cubic Ce{sub 1-x}Zr{sub x}O{sub 2-y} is persistent and is 8% in phase amount even at 90% zirconia with 33 nm crystal size. Neither the monoclinic phase m nor the tetragonal phase t{prime} is observed in the present nanoparticles (<40 nm). The effectiveness of these nanoparticles as oxygen source-and-sink in catalytic support is largely due to the persistence of the cubic and the t{prime}{prime} phases.

Authors:
; ; ; ;
Publication Date:
Research Org.:
Brookhaven National Laboratory (BNL) National Synchrotron Light Source
Sponsoring Org.:
Doe - Office Of Science
OSTI Identifier:
914064
Report Number(s):
BNL-78632-2007-JA
Journal ID: ISSN 0002-7820; JACTAW; TRN: US0801513
DOE Contract Number:
DE-AC02-98CH10886
Resource Type:
Journal Article
Resource Relation:
Journal Name: J. Am. Ceram. Soc.; Journal Volume: 80; Journal Issue: 3
Country of Publication:
United States
Language:
English
Subject:
43 PARTICLE ACCELERATORS; AIR; OXIDES; OXYGEN; PARTICLE SIZE; RAMAN SPECTROSCOPY; SOLUBILITY; TRANSMISSION ELECTRON MICROSCOPY; X-RAY DIFFRACTION; NSLS; national synchrotron light source

Citation Formats

Zhang,F., Chen, C., Hanson, J., Herman, I., and Chan, S. Phases in ceria-zirconia binary oxide (1-x)CeO2-xZrO2 nanoparticles: the size effects. United States: N. p., 2006. Web. doi:10.1111/j.1551-2916.2005.00788.x.
Zhang,F., Chen, C., Hanson, J., Herman, I., & Chan, S. Phases in ceria-zirconia binary oxide (1-x)CeO2-xZrO2 nanoparticles: the size effects. United States. doi:10.1111/j.1551-2916.2005.00788.x.
Zhang,F., Chen, C., Hanson, J., Herman, I., and Chan, S. Sun . "Phases in ceria-zirconia binary oxide (1-x)CeO2-xZrO2 nanoparticles: the size effects". United States. doi:10.1111/j.1551-2916.2005.00788.x.
@article{osti_914064,
title = {Phases in ceria-zirconia binary oxide (1-x)CeO2-xZrO2 nanoparticles: the size effects},
author = {Zhang,F. and Chen, C. and Hanson, J. and Herman, I. and Chan, S.},
abstractNote = {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 t{prime}{prime} and t monotonically moves toward higher zirconia concentrations with decreasing particle size. A smaller particle size increases the solubility of zirconia in cubic ceria, while higher zirconia content in ceria stabilizes against coarsening. In particular, the cubic Ce{sub 1-x}Zr{sub x}O{sub 2-y} is persistent and is 8% in phase amount even at 90% zirconia with 33 nm crystal size. Neither the monoclinic phase m nor the tetragonal phase t{prime} is observed in the present nanoparticles (<40 nm). The effectiveness of these nanoparticles as oxygen source-and-sink in catalytic support is largely due to the persistence of the cubic and the t{prime}{prime} phases.},
doi = {10.1111/j.1551-2916.2005.00788.x},
journal = {J. Am. Ceram. Soc.},
number = 3,
volume = 80,
place = {United States},
year = {Sun Jan 01 00:00:00 EST 2006},
month = {Sun Jan 01 00:00:00 EST 2006}
}
  • No abstract prepared.
  • Highlights: Black-Right-Pointing-Pointer A rapid and efficient microwave method was applied for synthesis of nano ceria. Black-Right-Pointing-Pointer Changing precursor has great effects on optical properties and size of nano ceria. Black-Right-Pointing-Pointer Fabrication of ceria nanoparticles using Ce{sup 4+} salts leads to better results. Black-Right-Pointing-Pointer Band gap energies of ceria nanoparticles were evaluated by UV-vis spectroscopy. -- Abstract: Cerium oxide, ceria (CeO{sub 2}), is one of the favourable nanoparticles (NPs) that possesses many remarkable properties so that it can be used in medicine, chemistry, environment, energy, information, industry, and so on. In this study, the crystalline ceria NPs were successfully prepared bymore » an efficient microwave-assisted heating technique from an aqueous solution using different cerium salts (Ce(IV) and Ce(III) salts). The products were characterized by X-ray powder diffraction (XRD), transmission electron microscope (TEM), FTIR spectroscopy, Raman spectroscopy, and UV-vis absorption spectroscopy. The results revealed that changing the precursor led to great effects on size, band gap energy, and the reaction time of preparing the ceria NPs. The significant feature of this manuscript is that the effects of different precursors on the structural and optical properties of ceria NPs were investigated for the first time. The average particle size of different samples was below 8 nm.« less
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  • In this study, scanning tunnelling microscopy has been used to study the morphology of an overlayer of ceria in contact with a TiO 2(110) substrate. Two types of domains were observed after ceria deposition. An ordered ceria film covered half of the surface and high-resolution imaging suggested a near-c(6 × 2) relationship to the underlying TiO 2(110)-(1 × 1). The other half of the surface comprised CeO x nanoparticles and reconstructed TiOx supported on TiO 2(110)-(1 × 1). Exposure to a small amount of gold resulted in the formation of isolated gold atoms and small clusters on the ordered ceriamore » film and TiO 2(110)-(1 × 1) areas, which exhibited significant sintering at 500 K and showed strong interaction between the sintered gold clusters and the domain boundaries of the ceria film. The Au/CeO x/TiO 2(110) model system proved to be a good catalyst for the water–gas shift (WGS) exhibiting much higher turnover frequencies (TOFs) than Cu(111) and Pt(111) benchmarks, or the individual Au/TiO 2(110) and Au/CeO 2(111) systems. For Au/CeO x/TiO 2(110) catalysts, there was a decrease in catalytic activity with increasing ceria coverage that correlates with a reduction in the concentration of Ce 3+ formed during WGS reaction conditions.« less