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Influence of the composition of a H2-CH4 gas mixture on the catalytic synthesis of carbon nanotubes-Fe/Fe3C-Al2O3 nanocomposite powders

Peigney, Alain and Laurent, Christophe and Rousset, Abel Influence of the composition of a H2-CH4 gas mixture on the catalytic synthesis of carbon nanotubes-Fe/Fe3C-Al2O3 nanocomposite powders. (1999) Journal of Materials Chemistry, 9 (5). 1167-1177. ISSN 0959-9428

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Official URL: http://dx.doi.org/10.1039/a809114e

Abstract

CNTs–Fe/Fe3C–Al2O3 nanocomposite powders have been prepared by selective reduction of an a-Al1.9Fe0.1O3 solid solution in H2–CH4 gas mixtures (0, 1.5, 3, 4.5, 6, 9, 12, 14, 16, 18, 24, 30 and 45 mol% CH4). The powders have been studied using macroscopic and microscopic techniques. The CNTs are arranged in very long bundles homogeneously dispersed in the composite powder. Most CNTs have less than four walls and are free of pyrolytic or amorphous carbon deposits. The inner diameter is in the range 1–6 nm, which could indicate that the catalyst particles active for CNTs formation are in this size range. The reduction of the Fe3+ ions to metallic Fe is highly favoured by the presence of CH4 in the reduction atmosphere. There are more Fe3C than a-Fe particles located at the surface of the matrix grains for CH4 contents higher than 4.5 mol%, however, the exact nature of the catalytically active particles remains an open question. Compositions in the range 9–18 mol% CH4 give the best.

Item Type:Article
Additional Information:Thanks to Royal Society of Chemistry. The definitive version is available at http://pubs.rsc.org/en/Content/ArticleLanding/1999/JM/a809114e#!divAbstract
HAL Id:hal-00940033
Audience (journal):International peer-reviewed journal
Uncontrolled Keywords:
Institution:French research institutions > Centre National de la Recherche Scientifique - CNRS (FRANCE)
Université de Toulouse > Université Toulouse III - Paul Sabatier - UPS (FRANCE)
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Deposited By: cirimat webmestre
Deposited On:31 Jan 2014 10:36

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