Structure, morphology and surface properties of nanostructured ZrO2 particles

• Published in: Journal of materials chemistry Vol. 9; no. 5; pp. 1203 - 1209
• Main Authors: BENFER, S, KNÖZINGER, E
• Format: Journal Article
• Language: English
• Published: Cambridge Royal Society of Chemistry 1999
• Subjects: Clusters, nanoparticles, and nanocrystalline materials; Condensed matter: structure, mechanical and thermal properties; Exact sciences and technology; Nanoscale materials: clusters, nanoparticles, nanotubes, and nanocrystals; Physics; Structure of solids and liquids; crystallography; Inorganic compounds; Transition element compounds; Surfaces; Binary compounds; XRD; Ultrafine particle; Infrared spectra; Experimental study; CVD; Local structure; Zirconium oxides; Morphology; Chemical preparation; TEM; Nanocrystal; Crystal structure
• ISSN: 0959-9428; 1364-5501
• DOI: 10.1039/a809164a

ZrO2 is of increasing interest in heterogeneous catalysis. Nanocrystalline CVD ZrO2 particles were produced by XRD thermal decomposition of a liquid metal organic precursor in a flow reactor system. XRD patterns show that the powder consists of a mixture of the monoclinic and tetragonal phase and that the phase fractions depend on the experimental conditions during the preparation as well as on the subsequent heat treatment of the sample. The mean particle diameter of the synthesised powders is about 4-5 nm as estimated from the line width of Bragg reflections and from transmission electron micrographs. The crystallites are non-porous and exhibit a rough surface incorporating a high concentration of low-coordinated surface sites. In agreement with the small particle size, the powder has a high specific surface area (over 200 m2/g), which exceeds that of commercially available materials by a factor of more than 3. The structure and morphology of the particles is essentially preserved during extensive heat treatment up to 500 C. Hydroxyl groups as IR active surface probes clearly indicate that the phase fractions on the surface and in the bulk strongly differ from each other. Low-coordinated OH groups on monoclinic surface domains give rise to H/D exchange reactions with D2 already at room temperature. They are revealed and monitored over time by FTIR spectroscopy. 29 refs.