TiO2 supported Pt based bimetallic nanocatalysts were prepared by impregnation method and reduced at two different temperatures, 375 °C and 575 °C for the selective hydrogenation of citral to the corresponding unsaturated alcohols namely; geraniol (GOL) and nerol (NOL). The catalysts were characterized by BET surface area measurement, FT-IR, SEM, EDAX, TEM, XRD and XPS. The prepared nanocatalysts are uniformly dispersed with an average particles size 50-100 nm and zero valence metallic state. The SMSI (Strong Meal-Support Interaction) effect shows that the catalysts reduced at higher temperature leads to an increase in selectivity toward unsaturated alcohols (GOL & NOL) for Pt-Ru/TiO2 compared to Pt-Pd/TiO2 and Pt-Au/TiO2 nanocatalysts. In addition a second metal (Ru) also leads to an increase of the GOL & NOL selectivity during the citral hydrogenation. The generated partially oxidized second metal species due to the difference in electronegativity, strongly binds the C=O group and also paves the way for the selective activation of the C=O bond. Metal support interaction and promoter active metal interaction increased the unsaturated alcohol formation.
Bimetallic nanocatalysts, TiO2 supported, SMSI effect, Thermal reduction, Citral hydrogenation, Unsaturated alcohols