Nickel Based Catalysts for Selective Hydrogenation of Cinnamaldehyde- Influence of Support Phases

Abstract

of supports; polymorphs of titania; nickel at interface Ni (15% w/w) supported on alumina, silica, and titania (P-25, anatase and rutile phases) have been investigated for the liquid phase hydrogenation of cinnamaldehyde. XRD, TPR and XPS data (binding energy shifts for Ni2p) indicate metal-support interactions in all supported catalysts. Weaker binding of H2 on Ni/TiO2 (H2-TPD) improves activity. Ni/TiO2 phases display higher cinnamaldehyde conversion and selectivity to cinnamyl alcohol compared to the catalysts supported on alumina and silica. Amongst the three polymorphs of titania, the maximum activity, and selectivity displayed by Ni/ TiO2-P-25, is attributed to the active Ni crystallites located at the interface between anatase and rutile phases in titania P-25 matrix (HRTEM). Though Ni crystallites on alumina and silica are relatively smaller (compared to those on the three TiO2 phases) in size, their activity vis-à-vis for those supported on titania phases is less, implying that factors other than crystallite size influence the performance.