Electrical properties and reactivity under air-CO flows of composite systems based on ceria coated carbon nanotubes

Marjorie David (1) , Madjid Arab (1) , Frédéric Guinneton (1) , Emmanuel Flahaut (2) , Bahcine Bakiz (1) , Pawel Nowakowski (1) , Jean-Raymond Gavarri (1)

1 IM2NP - Institut des Matériaux, de Microélectronique et des Nanosciences de Provence
2 CIRIMAT - Centre interuniversitaire de recherche et d'ingenierie des matériaux

Nanocomposite systems of ceria nanoparticles and Double Walled Carbon Nanotubes (DWNTs) coated with nanoceria (nCeO2) were elaborated using a classical sol gel method. Three samples noted as [nCeO2 + xDWNTs] with variable weight fractions x = 0, 5 and 15 wt.% of DWNTs were obtained. The samples were characterized by Xray diffraction and electron microscopy. The electrical conductivity of [nCeO2 + xDWNTs] compacted pellets systems was determined from electrical impedance spectrometry, under air, between 120 and 400 °C. In this temperature range, all samples were semiconducting with a weak variation of activation energy. However, the conductivity strongly increased with the weight fraction of ceria coated carbon nanotubes. Finally, the solid-gas interactions between air-CO flows and these systems were studied as a function of time and temperature, by means of Fourier transform infrared (FTIR) spectroscopy. The oxidation kinetics of CO into CO2 was analyzed from the evolutions of FTIR absorption band intensities. As the carbon nanotube fraction x increased, the conversion efficiency was strongly improved.

Mots clés: Carbon nanotubes; Cerium dioxide; Microstructural analyses; Electrical conduction; Infrared spectroscopy; Solid-gas interactions; Carbon nanotubes

Domaines: Génie chimique; Micro et nanotechnologies/Microélectronique

Marjorie David, Madjid Arab, Frédéric Guinneton, Emmanuel Flahaut, Bahcine Bakiz, et al.. Electrical properties and reactivity under air-CO flows of composite systems based on ceria coated carbon nanotubes. Chemical Engineering Journal, 2011, vol. 171, pp. 272-278. ⟨10.1016/j.cej.2011.03.079⟩. ⟨hal-00857438⟩