An original growth mode of MWCNTs on alumina supported iron catalysts
| Autor: | Dominique Plee, Yolande Kihn, Régis Philippe, Philippe Serp, Philippe Kalck, Brigitte Caussat, Patrice Gaillard, Andrea Falqui, Daniel Bernard, Serge Bordere |
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| Přispěvatelé: | Laboratoire de chimie de coordination (LCC), Institut de Chimie de Toulouse (ICT), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Génie Chimique (LGC), Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT), Centre d'élaboration de matériaux et d'études structurales (CEMES), Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut de Chimie de Toulouse (ICT), Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Istituto Italiano di Tecnologia - IIT (ITALY), Institut National Polytechnique de Toulouse - Toulouse INP (FRANCE), Arkema (FRANCE), Université Toulouse III - Paul Sabatier - UT3 (FRANCE), Centre National de la Recherche Scientifique - CNRS (FRANCE) |
| Jazyk: | angličtina |
| Rok vydání: | 2009 |
| Předmět: |
Iron catalyst
Chemistry Oxide Iron oxide Nanoparticle Nanotechnology Multi-walled carbon nanotubes Chemical vapor deposition Catalysis Thermogravimetry Vertically aligned carbon nanotubes chemistry.chemical_compound Adsorption [CHIM.GENI]Chemical Sciences/Chemical engineering Chemical engineering Génie chimique Thin film Physical and Theoretical Chemistry |
| Zdroj: | Journal of Catalysis Journal of Catalysis, 2009, 2 (2), pp.345-358. ⟨10.1016/j.jcat.2009.02.027⟩ |
| ISSN: | 0021-9517 1090-2694 |
| DOI: | 10.1016/j.jcat.2009.02.027⟩ |
| Popis: | Multi-walled carbon nanotubes (MWCNTs) have been produced from ethylene by fluidized bed-catalytic chemical vapor deposition (FB-CCVD) on alumina supported iron catalyst powders. Both catalysts and MWCNTs-catalyst composites have been characterized by XRD, SEM-EDX, TEM, Mossbauer spectroscopy, TGA and nitrogen adsorption measurements at different stages of the process. The fresh catalyst is an alumina/iron oxide powder composed of amorphous iron(III) oxide nanoparticles located inside the porosity of the alumina support and of a micrometric crystalline α-iron(III) oxide surface film. The beginning of the CVD process provokes a brutal reconstruction and simultaneous carburization of the surface film that allows MWCNT nucleation and growth. These MWCNTs grow aligned between the support and the surface catalytic film, leading to a uniform consumption and uprising of the film. When the catalytic film has been consumed, the catalytic particles located inside the alumina porosity are slowly reduced and activated leading to a secondary MWCNT growth regime, which produces a generalized grain fragmentation and entangled MWCNT growth. Based on experimental observations and characterizations, this original two-stage growth mode is discussed and a general growth mechanism is proposed. |
| Databáze: | OpenAIRE |
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