Liquid phase selective hydrogenation of citral over Ru/Tio2 and Pt/Tio2 nano catalysts

Nano supported Ru/TiO₂ and Pt/TiO₂ catalysts were prepared by impregnation method, dried in a furnace, calcined at 400°C for 5 hours and reduced at two different temperatures, 375°C (LTR) and 575°C (HTR) for 4 hours. The catalysts were characterized by BET surface area, TPR, HRTEM, XRD and XPS techniques. The activity and selectivity of the catalysts were evaluated in liquid phase selective hydrogenation of citral in a semi-batch Parr reactor at 90°C and a hydrogen pressure of 10 MPa and solvent medium of a isopropanol during 6 hours. Amongst the studied catalysts, 1.5%Pt/TiO₂ reduced at 575°C had presented higher selectivity in terms of citral towards unsaturated alcohols (Geraniol and Nerol). This is the influence of strong metal support interaction (SMSI effect) of the catalysts towards the selective activation of C=0 hydrogenation. These environment friendly nano catalysts can be recycled for more than 12 cycles and the activity is retained upto 85%.