Structure, microstructure, and size dependent catalytic properties of nanostructured ruthenium dioxide

Journal Article · Thu May 15 00:00:00 EDT 2008 · Journal of Solid State Chemistry

DOI:https://doi.org/10.1016/j.jssc.2008.01.047· OSTI ID:21128276

Nowakowski, Pawel; Dallas, Jean-Pierre; Villain, Sylvie ^[1]; Kopia, Agnieszka ^[2]; Gavarri, Jean-Raymond ^[1]

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1. Universite du Sud Toulon Var, IM2NP, UMR CNRS 6242, BP 20132, 83 957 LA GARDE (France)
2. University of Science and Technology, AGH, Al. Mickiewicza 30, 30 059 Cracow (Poland)

Nanostructured powders of ruthenium dioxide RuO{sub 2} were synthesized via a sol gel route involving acidic solutions with pH varying between 0.4 and 4.5. The RuO{sub 2} nanopowders were characterized by X-ray diffraction, scanning and transmission electron microscopy (SEM and TEM). Rietveld refinement of mean crystal structure was performed on RuO{sub 2} nanopowders and crystallized standard RuO{sub 2} sample. Crystallite sizes measured from X-ray diffraction profiles and TEM analysis varied in the range of 4-10 nm, with a minimum of crystallite dimension for pH=1.5. A good agreement between crystallite sizes calculated from Williamson Hall approach of X-ray data and from direct TEM observations was obtained. The tetragonal crystal cell parameter (a) and cell volumes of nanostructured samples were characterized by values greater than the values of standard RuO{sub 2} sample. In addition, the [Ru-O{sub 6}] oxygen octahedrons of rutile structure also depended on crystal size. Catalytic conversion of methane by these RuO{sub 2} nanostructured catalysts was studied as a function of pH, catalytic interaction time, air methane composition, and catalysis temperature, by the way of Fourier transform infrared (FTIR) spectroscopy coupled to homemade catalytic cell. The catalytic efficiency defined as FTIR absorption band intensities I(CO{sub 2}) was maximum for sample prepared at pH=1.5, and mainly correlated to crystallite dimensions. No significant catalytic effect was observed from sintered RuO{sub 2} samples. - Graphical abstract: Nanosized crystals of RuO{sub 2} prepared by sol gel route, at pH=0.4 and 1.5. Mean size values <D>, respectively, 10 and 8 nm.

• OSTI ID: 21128276
• Journal Information: Journal of Solid State Chemistry, Vol. 181, Issue 5; Other Information: DOI: 10.1016/j.jssc.2008.01.047; PII: S0022-4596(08)00057-1; Copyright (c) 2008 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved; Country of input: International Atomic Energy Agency (IAEA); ISSN 0022-4596
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
ABSORPTION
ABSORPTION SPECTROSCOPY
CATALYSIS
CRYSTAL STRUCTURE
CRYSTALS
INFRARED SPECTRA
MICROSTRUCTURE
NANOSTRUCTURES
PH VALUE
RUTHENIUM OXIDES
RUTILE
SCANNING ELECTRON MICROSCOPY
SOL-GEL PROCESS
TRANSMISSION ELECTRON MICROSCOPY
X-RAY DIFFRACTION