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In this study, we report on the preparation, characterization and use of new catalytic polymeric microcapsules for the selective oxidation of benzyl alcohols to benzaldehydes. The catalyst, ammonium molybdate tetrahydrate, was entrapped inside modified polyetheretherketone (PEEKWC) polymeric microcapsules during their preparation. Catalytic activity of the new PEEKWC microcapsules has been evaluated in the oxidation of substituted benzyl alcohols to benzaldehydes using hydrogen peroxide as oxidant. EDX analysis of the catalytic microcapsules showed a satisfactorily catalyst distribution on the shell and on the inner core. Proof of successful entrapment of catalyst inside polymeric matrix during the preparation was given by the different colorimetric reactions between the catalytic PEEKWC microcapsules and the oxidant (hydrogen peroxide). An interesting structure-reactivity behaviour, that may indeed be induced by the interaction between the polymeric membrane and the substrate, has been observed. PEEKWC catalytic microcapsules were stable under oxidation conditions and can be recycled without a loss of activity.

Novel polyvinylidene fluoride (PVDF) porous microcapsule membranes were successfully prepared with non-solvent induced phase inversion method for the immobilization of catalyst ammonium molybdate tetrahydrate ((NH 4 ) 6 Mo 7 O 24 ·4H 2 O). The chemical–physical analysis of the new PVDF catalytic microcapsules was carried out by means of SEM, EDX, IR, DSC and XRD techniques. Catalytic activity of the PVDF catalytic microcapsules has been evaluated in the oxidation of benzyl alcohol to benzaldehyde in solvent free conditions. The polymeric microcapsules “keep in contact” the two phases: the organic phase, containing the substrate and the product, and the aqueous phase with the oxidant, H 2 O 2 . In literature, ((NH 4 ) 6 Mo 7 O 24 ·4H 2 O) was reported to be effective in the oxidation of alcohols with H 2 O 2 in combination with a phase transfer catalyst in chlorinated solvents. The effect of reaction temperature, substrate:oxidant ratio, swelling of polymeric microcapsules on the reaction progress was investigated. PVDF catalytic microcapsules have given proof of their complete stability under oxidation conditions and their good recycle.