Vapour phase hydrogenation of cinnamaldehyde over silica supported transition metal-based bimetallic catalysts

A series of silica supported transition metal-based bimetallic catalysts M-M-1/SiO2 (M=Co, Ni, and Cu; M-1 =Ni, Cu, and Co) were prepared by deposition-precipitation method. Nitrate salts of the corresponding transition metals and colloidal silica were used as the precursors. The physicochemical characteristics of the prepared catalysts were investigated by means of X-ray powder diffraction, thermogravimetry, FT-infrared, scanning electron microscopy-energy dispersive X-ray analysis, and BET surface area techniques. These catalysts were evaluated for selective hydrogenation of cinnamaldehyde to cinnamyl alcohol in the vapour phase at normal atmospheric pressure. Among the various catalysts investigated, the Cu-Co/SiO2 combination catalyst exhibited very promising results for the selective hydrogenation of cinnamaldehyde to cinnamyl alcohol, whereas Co-Ni/SiO2 and Ni-Cu/SiO2 bimetallic catalysts provided good yields of hydrocinnamaldehyde. (c) 2005 Elsevier B.V. All rights reserved.