Formation and Acid–Base Surface Properties of Highly Dispersed η-Al{sub 2}O{sub 3} Nanopowders

Journal Article · Sun Apr 15 04:00:00 EDT 2018 · Inorganic Materials

DOI:https://doi.org/10.1134/S0020168518040052· OSTI ID:22788151

Kotlovanova, N. E.; Matveeva, A. N.; Omarov, Sh. O. ^[1]; Sokolov, V. V. ^[2]; Akbaeva, D. N. ^[3]

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1. St. Petersburg State Technological Institute (Technical University) (Russian Federation)
2. Ioffe Institute (Russian Federation)
3. Al-Farabi Kazakh National University (Kazakhstan)

Highly dispersed η-Al{sub 2}O{sub 3}-based nanopowders have been prepared via glycine–nitrate combustion followed by heat treatment in air. The resultant materials have been characterized by X-ray diffraction, Fourier transform IR spectroscopy, scanning electron microscopy, simultaneous thermal analysis, and other techniques. We have optimized the glycine-to-nitrate ratio (G/N = 0.2) and found heat treatment conditions for combustion products (isothermal holding at a temperature of 700°C for 6 h) that allow one to obtain single- phase nanocrystalline η-Al{sub 2}O{sub 3} powders with an average particle size of 5 ± 1 nm and specific surface area of 54 ± 5 m{sup 2}/g. The acid–base surface properties of the η-Al{sub 2}O{sub 3} nanopowder have been analyzed using pyridine sorption–desorption processes as an example. The specific concentrations of weak, intermediate, and strong Lewis acid centers on the surface of the η-Al{sub 2}O{sub 3} nanocrystals have been shown to markedly exceed those on the surface of commercially available γ-Al{sub 2}O{sub 3} (A-64). The synthesized nanopowders can thus be used as effective supports of acid catalysts.

• OSTI ID: 22788151
• Journal Information: Inorganic Materials, Journal Name: Inorganic Materials Journal Issue: 4 Vol. 54; ISSN INOMAF; ISSN 0020-1685
• Country of Publication: United States
• Language: English

Related Subjects

77 NANOSCIENCE AND NANOTECHNOLOGY
AIR
ALUMINIUM OXIDES
CATALYSTS
COMBUSTION PRODUCTS
CRYSTALS
FOURIER TRANSFORM SPECTROMETERS
GLYCINE
HEAT TREATMENTS
INFRARED SPECTRA
LEWIS ACIDS
NANOSTRUCTURES
NITRATES
POWDERS
PYRIDINE
SCANNING ELECTRON MICROSCOPY
SPECIFIC SURFACE AREA
SURFACE PROPERTIES
THERMAL ANALYSIS
X-RAY DIFFRACTION