Hybrid peroxotungstophosphate organized catalysts highly active and selective in alkene epoxidation

• Heterogenization by a hybridization method of catalytic peroxo species is proposed.
• Hydrophobic environment enhances the selectivity of the hybrid catalyst.
• Electrostatic hybridization is enough to avoid leaching of active species.
• No deactivation by product over-adsorption is observed.

Heterogenization of homogeneous catalysts is still a challenge but can improve drastically the processability of these compounds. Hybridization of polyoxometalates offers an efficient heterogenization route of homogeneous epoxidation catalysts. The Keggin [PW12O40]3 − and the Ventruello {PO4[WO(O2)2]4}3 − species were inserted by electrostatic interactions in a poly(ampholytic) polymeric matrix in order to prevent the leaching of these species. The presence of the polymeric matrix allows to tune the catalyst performance in cyclooctene epoxidation and to improve the selectivity to epoxide. Indeed, the hydrophobicity of the matrix induces a quick desorption of hydrophilic epoxide species. Their over-oxidation and the catalyst species deactivation by over-adsorption of epoxide are then avoided.

Figure optionsDownload as PowerPoint slide