title: Efficiency of Polyoxometalate-Based Mesoporous Hybrids as Covalently Anchored Catalysts.
abstract: Polyoxometalate (POM) hybrids have been covalently immobilized through the formation of amide bonds on several types of mesoporous silica. This work allows the comparison of three POM-based mesoporous systems, obtained with three different silica supports in which either the organic functions of the support (amine vs carboxylic acid) and/or the structure of the support itself (SBA-15 vs mesocellular foams (MCF)) were varied. The resulting POM-based mesoporous systems have been studied in particular by high resolution transmission electronic microscopy (HR-TEM) in order to characterize the nanostructuration of the POMs inside the pores/cells of the different materials. We thus have shown that the best distribution and loading in POMs have been reached with SBA-15 functionalized with aminopropyl groups. In this case, the formation of amide bonds in the materials has led to the nonaggregation of the POMs inside the channels of the SBA-15. The catalytic activity of the anchored systems has been evaluated through the epoxidation of cyclooctene and cyclohexene with H2O2 in acetonitrile. The reactivity of the different grafted POMs hybrids has been compared to that in solution (homogeneous conditions). Parallels can be drawn between the distribution of the POMs and the activity of the supported systems. Furthermore, recycling tests together with catalyst filtration experiments during the reaction allowed us to preclude the hypothesis of a significant leaching of the supported catalyst.
authors.affiliation: †Sorbonne Universités, UPMC-Paris 06, UMR 8232, Institut Parisien de Chimie Moléculaire, 4 Place Jussieu, F-75005 Paris, France.|‡CNRS, UMR 8232, Institut Parisien de Chimie Moléculaire, 4 Place Jussieu, F-75005 Paris, France.
authors.forename: Faiza
authors.initials: F
authors.lastname: Bentaleb
authors.affiliation: †Sorbonne Universités, UPMC-Paris 06, UMR 8232, Institut Parisien de Chimie Moléculaire, 4 Place Jussieu, F-75005 Paris, France.|‡CNRS, UMR 8232, Institut Parisien de Chimie Moléculaire, 4 Place Jussieu, F-75005 Paris, France.
authors.forename: Ourania
authors.initials: O
authors.lastname: Makrygenni
authors.affiliation: §Sorbonne Universités, UPMC-Paris 06, UMR 7197, Laboratoire de Réactivité de Surface, site Le Raphael, Bat. A/B, 3 rue Galilée, 94200 Ivry-sur-Seine, France.|∥CNRS, UMR 7197, Laboratoire de Réactivité de Surface, site Le Raphael, Bat. A/B, 3 rue Galilée, 94200 Ivry-sur-Seine, France.
authors.forename: Dalil
authors.initials: D
authors.lastname: Brouri
authors.affiliation: ⊥Sorbonne Universités, UPMC-Paris 06, IMPC FR CNRS 2482, Collège de France, 11 place Marcelin Berthelot, 75231 Paris Cedex 05, France.
authors.forename: Cristina
authors.initials: C
authors.lastname: Coelho Diogo
authors.affiliation: #UMR CNRS 5253 Institut Charles Gerhardt, Chimie Moléculaire et Organisation du Solide, Université Montpellier, cc1701, Place E. Bataillon 34095 Montpellier, France.
authors.forename: Ahmad
authors.initials: A
authors.lastname: Mehdi
authors.affiliation: †Sorbonne Universités, UPMC-Paris 06, UMR 8232, Institut Parisien de Chimie Moléculaire, 4 Place Jussieu, F-75005 Paris, France.|‡CNRS, UMR 8232, Institut Parisien de Chimie Moléculaire, 4 Place Jussieu, F-75005 Paris, France.
authors.forename: Anna
authors.initials: A
authors.lastname: Proust
authors.affiliation: §Sorbonne Universités, UPMC-Paris 06, UMR 7197, Laboratoire de Réactivité de Surface, site Le Raphael, Bat. A/B, 3 rue Galilée, 94200 Ivry-sur-Seine, France.|∥CNRS, UMR 7197, Laboratoire de Réactivité de Surface, site Le Raphael, Bat. A/B, 3 rue Galilée, 94200 Ivry-sur-Seine, France.
authors.forename: Franck
authors.initials: F
authors.lastname: Launay
authors.affiliation: †Sorbonne Universités, UPMC-Paris 06, UMR 8232, Institut Parisien de Chimie Moléculaire, 4 Place Jussieu, F-75005 Paris, France.|‡CNRS, UMR 8232, Institut Parisien de Chimie Moléculaire, 4 Place Jussieu, F-75005 Paris, France.
authors.forename: Richard
authors.initials: R
authors.lastname: Villanneau