Journal of catalysis vol:163 issue:2 pages:457-464
Cyclohexane is selectively oxidized by tertiary-butyl hydroperoxide at room temperature using a catalyst consisting of iron phthalocyanine in zeolite Y (FePcY) occluded in a polydimethylsiloxane (PDMS) membrane. Different experimental setups are used to study the effect of the membrane incorporation on the catalytic performance. Embedding this catalyst in PDMS results in a new system with considerably higher activity which makes the controlled addition of peroxide redundant. Separating the two immiscible reactant phases, the membrane eliminates the need for a solvent. In addition, it actively controls the concentration of the reactants near the active sites by fine-tuning their respective sorptions. The result is a substrate/oxidant ratio which is beneficial for the reaction. Evidence for this active role is established in the analysis of the composition of the membrane phase after reaction. (C) 1996 Academic Press Inc.