II International Symposium on Carbon for Catalysis ABSTRACTS

OP-I-3
BI-METALLIC CATALYSIS ON CARBON NANOTUBES FOR THE SELECTIVE
HYDROGENATION OF CINNAMALDEHYDE
Vu H., Gonçalves F., Philippe R., Lamouroux E., Corrias M. 1 , Kihn Y., Kalck P., Serp P.
1 Laboratoire de Catalyse, Chimie Fine et Polymères, Ecole Nationale Supérieure
d’Ingénieurs en Arts Chimiques Et Technologiques, 118 Route de Narbonne, 31077 Toulouse
Cedex 4, France
2 CEMES-CNRS n°8001, 2 rue Jeanne Marvig 31055 Toulouse, France
e-mail: Philippe.Serp@ensiacet.fr
Nanostructured carbon materials have already been successfully used in heterogeneous
catalysis, but, unfortunately, a lack of systematic comparison with traditional activated carbon
supported catalysts has to be noted. [1,2]. Additionally, there is very scarce studies dealing
with the comparison of catalysts prepared on the different types of fibrous carbon, namely,
multi-walled carbon nanotubes (MWNT), single-walled carbon nanotubes (SWNT) and
graphite nanofibers (GNF).
Carbon nanotubes (MWNT, GNF, SWNT) based catalysts (Pt, Ru and Pt-Ru) were
developed and compared to their counterparts on activated carbon for the selective reduction
of cinnamaldehyde to its unsaturated alcohol. Prior to metals impregnation, the carbon
supports were oxidised, in order to develop oxygen containing surface groups to act as
anchoring sites for the precursors. Platinum and ruthenium were deposited on the different
carbon supports by means of a surface organometallic approach, using [Pt(CH 3 ) 2 (η 4 -C 8 H 12 )]
and [Ru(η 4 -C 8 H 12 )(η 6 -C 8 H 10 )] as precursors. The use of mesoporous nanostructured support
that decreases the mass transfer limitations allows significantly better activity than
microporous activated carbon. As far as selectivity is concerned, activated carbon systems are
more selective towards cinnamyl alcohol formation. The use of a platinum ruthenium
bimetallic system (Fig. 1) permits to reach higher selectivities than with the monometallic
systems. Finally, we demonstrate that, in the case of MWNT supported systems, high
temperatures catalyst activation does promote significantly the selectivity towards cinnamyl
alcohol (Fig. 2). The role of this high temperature treatments, which may affect the electrical
conductivity of the support, the mean particle size, the cinnamaldehyde equilibrium
adsorption and the electron transfer from the MWNT to the metal will be discussed.
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