II International Symposium on Carbon for Catalysis ABSTRACTS

CONTROLLING DIAMETER AND PRESENCE OF DEFECTS OF MULTI
PP-I-28
WALLED CARBON NANOTUBES BY CVD OVER Fe/Co SBA-15 CATALYSTS
Lanzafame P. 1,3 , Perathoner S. 1,3 , Centi G. 1,3 , Su D. 2,3 , Schlögl R. 2,3
1 Department of Industrial Chemistry and Eng. of Materials, University of Messina and
UdR-Messina of INSTM Messina, Italy
2 Department of Inorganic Chemistry, Fritz-Haber-Institut der Max-Planck-Gesellschaft,
Berlin, Germany
3 ELCASS, European Laboratory of Catalysis and Surface Science
e-mail: planzafame@ingegneria.unime.it
The use of carbon nanotubes (CNT) opens new perspectives in electronics, sensors,
nanoelectromechanical systems, and in the field of catalysis. The diameter and chirality of
CNT determine their physical and chemical properties, but still there are limited data on how
to control these properties. Limiting to the synthesis of CNT by catalytic hydrocarbon
decomposition over metal particles (usually Fe, Co, Ni), because this is one of the preferable
methods for larger-scale and low-cost production, it was reported by different authors that the
CNT diameter depends on the metal particles size. However, it is unclear whether or not the
characteristics and modality of growing of the CNT could also depend on this parameter. Due
to the quite different range of reaction conditions, catalyst composition and type of feed used
by the different authors in literature, it is also not possible to derive clear information from
these results.
In order to contribute to clarify this question, we have prepared FeCo catalytic
nanoparticles stabilized inside an ordered mesoporous matrix (SBA-15) or located on the
external surface of this mesoporous matrix. The former FeCo particles have uniform size of
around 6 nm, the same size of the channels of the SBA-15 we used in this work, while the
particles located on the external crystals have a size slightly larger, of around 30 nm, as
shown by TEM characterization. Both types of particles have the same composition.
The synthesis of CNT was made by CVD of propane. Under exactly the same reaction
conditions, these two type of FeCo nanoparticles give rise to multiwalled carbon nanotubes
(MWCNT) with a diameter close to that of the catalyst nanoparticles, but having a different
way by which the graphene sheets are rolled up.
The amount and purity of the carbon nanotubes produced by C 3 H 8 -CVD over Fe/Co
SBA-15 catalyst was monitored by temperature programmed oxidation (TPO) in a
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