Active carbons as catalysts for liquid phase reactions

M. Besson (1) , P. Gallezot (1) , A. Perrard (1) , C. Pinel (1)

1 IRC - Institut de recherches sur la catalyse

Three examples of applications of activated carbons, including synthetic carbons obtained from polymers, in selective liq. phase org. reactions, are reported. It was shown that ruthenium supported on activated carbon cloths (ACC) obtained by carbonization of woven rayon fabric were very selective in the hydrogenation of glucose to sorbitol. This was attributed to an easy mass transfer from the micropores to the liq. phase which favors the fast desorption of sorbitol avoiding epimerization to mannitol. Synthetic carbons obtained by carbonization of cross-linked phenolic resins were active in the oxidn. with air of cyclic ketones (cyclohexanone, cyclododecanone, 3,3,5-trimethylcyclohexanone) to the corresponding dicarboxylic acids. The activity and selectivity depend upon treatments favoring the presence of surface functional groups, particularly quinone/carbonyl groups. The activated carbons obtained from natural sources can be modified by thermal treatments favoring the presence of basic sites which improve the rate of the oxidative decarboxylation of N-phosphonomethyl iminodiacetic acid to glyphosate. The nitrogen-contg. basic functions generated by high temps. thermal treatment of the activated carbon in NH3 were particularly active.

Domaines: Catalyse

M. Besson, P. Gallezot, A. Perrard, C. Pinel. Active carbons as catalysts for liquid phase reactions. Catalysis Today, 2005, 102-103, pp.160-165. ⟨hal-00009077⟩