Magnetic Fe 2 O 3 -SiO 2 -MeO 2 -Pt (Me = Ti, Sn, Ce) as catalysts for the selective hydrogenation of cinnamaldehyde. Effect of the nature of the metal oxide

Abstract

The type of metal oxide affects the activity and selectivity of Fe 2 O 3 -SiO 2 -MeO 2 -Pt (Me = Ti, Sn, Ce) catalysts on the hydrogenation of cinnamaldehyde. The double shell structure design is thought to protect the magnetic Fe 2 O 3 cores, and also act as a platform for depositing a second shell of TiO 2 , SnO 2 or CeO 2 metal oxide. To obtain a homogeneous metallic dispersion, the incorporation of 5 wt % of Pt was carried out over Fe 2 O 3 -SiO 2 -MeO 2 (Me = Ti, Sn, Ce) structures modified with (3-aminopropyl)triethoxysilane by successive impregnation-reduction cycles. The full characterization by HR-TEM, STEM-EDX, XRD, N 2 adsorption isotherm at -196 °C, TPR-H 2 and VSM of the catalysts indicates that homogeneous core-shell structures with controlled nano-sized magnetic cores, multi-shells and metallic Pt were obtained. The nature of the metal oxide affects the Pt nanoparticle sizes where the mean Pt diameter is in the order: -TiO 2 -Pt > -SnO 2 -Pt > -CeO