II International Symposium on Carbon for Catalysis ABSTRACTS

OP-I-14
HYBRID CATALYSTS OF Rh COMPLEXES ON CARBON MATERIALS
Lemus-Yegres L., Such-Basáñez I., Román-Martínez M.C., Salinas-Martínez de Lecea C.
Department of Inorganic Chemistry, University of Alicante. Ap. 99, E-03080 Alicante, Spain
e-mail: Lived.Lemus@ua.es
Introduction
Hybrid catalysts, consisting of a metal complex immobilized on a solid support, are
regarded as a novel system able to combine the advantages and to overcome the drawbacks of
heterogeneous and homogeneous catalysts. Carbon materials, with outstanding properties as
catalyst support (high versatility in textural properties and surface chemistry, chemical
stability in many conditions and easiness of active metal phase recovery), are also considered
to be suitable for this application. The present work reports the results obtained on the
immobilization of two rhodium complexes on carbon materials. The anchorage has been
carried out by the creation of a covalent bond between a ligand and the oxygen groups of the
carbon surface. Several carbon materials have been used as support: one granular and one
pelletized activated carbon, an activated carbon cloth and multiwalled carbon nanotubes.
These materials have been submitted to oxidation treatments in order to create specific
oxygen functionalities on the surface. The two hybrid catalysts prepared are schematically
shown in Figure 1.
Rh
NH 2
NH
Cl PPh 3
Rh
Ph 3 P
NH 2
O
O
O
Si
O
O
Catalyst type A
Catalyst type B
Figure 1.- Model of the anchorage through ester and siloxane bonds
Experimental
Catalysts type A: The carbon supports were oxidized with ammonium persulfate
(saturated solution of (NH 4 ) 2 S 2 O 8 in H 2 SO 4 1M 10mL/g carbon) and then treated with SOCl 2
(5mL in 5mL of toluene, 24h reflux) to create acyl chloride groups. The molecule 6-amino-1-
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