The effect of B{sub 2}O{sub 3} addition on the crystallization of amorphous TiO{sub 2}-ZrO{sub 2} mixed oxide

Journal Article · Thu Feb 15 04:00:00 EST 2007 · Journal of Solid State Chemistry

OSTI ID:21015674

Guanzhong, Lu ^[1]

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1. Research Institute of Applied Catalysis, Department of Chemical Engineering, Shanghai Institute of Technology, Number 120, Caobaolu, Shanghai 200235 (China)

The effect of B{sub 2}O{sub 3} addition on the crystallization of amorphous TiO{sub 2}-ZrO{sub 2} mixed oxide was investigated by X-ray diffraction (XRD), thermogravimetric and differential thermal analysis (TG/DTA). TiO{sub 2}-ZrO{sub 2} mixed oxide was prepared by co-precipitation method with aqueous ammonia as the precipitation reagent. Boric acid was used as a source of boria, and boria contents varied from 2 to 20 wt%. The results indicate that the addition of small amount of boria (<8 wt%) hinders the crystallization of amorphous TiO{sub 2}-ZrO{sub 2} into a crystalline ZrTiO{sub 4} compound, while a larger amount of boria ({>=}8 wt%) promotes the crystallization process. FT-IR spectroscopy and {sup 11}B MAS NMR results show that tetrahedral borate species predominate at low boria loading, and trigonal borate species increase with increasing boria loading. Thus it is concluded that highly dispersed tetrahedral BO{sub 4} units delay, while a build-up of trigonal BO{sub 3} promote, the crystallization of amorphous TiO{sub 2}-ZrO{sub 2} to form ZrTiO{sub 4} crystals. - Graphical abstract: The addition of small amount of boria (<8 wt%) hinders the crystallization of amorphous TiO{sub 2}-ZrO{sub 2} into a crystalline ZrTiO{sub 4} compound, while the larger amount of boria ({>=}8 wt%) promotes the crystallization process.

• OSTI ID: 21015674
• Journal Information: Journal of Solid State Chemistry, Journal Name: Journal of Solid State Chemistry Journal Issue: 2 Vol. 180; ISSN 0022-4596; ISSN JSSCBI
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
AMMONIA
BORATES
BORIC ACID
BORON OXIDES
COPRECIPITATION
CRYSTALLIZATION
DIFFERENTIAL THERMAL ANALYSIS
FOURIER TRANSFORMATION
INFRARED SPECTRA
NUCLEAR MAGNETIC RESONANCE
THERMAL GRAVIMETRIC ANALYSIS
TITANATES
TITANIUM OXIDES
X-RAY DIFFRACTION
ZIRCONIUM OXIDES