Selective hydrogenation of cinnamaldehyde to cinnamyl alcohol over Co/TiO_2-SiO_2 catalysts

A series of TiO2-SiO2 supported cobalt catalysts were prepared by using the incipient wetness impregnation method,and their activity and selectivity were evaluated for the selective hydrogenation of cinnamaldehyde to cinnamyl alcohol.The effects of Co loading,calcination temperature,reduction temperature and rare earth promoters on the hydrogenation performance of the catalysts were tested.The results showed that the catalytic performance of cobalt catalyst depended on the crystal size of Co on the catalyst surface.The catalyst with bigger Co crystals exhibited higher hydrogenation activity and selectivity of cinnamyl alcohol.The optimal cobalt loading,calcination temperature and reduction temperature of the catalyst for cinnamaldehyde hydrogenation were found to be 15%,823 K and 823 K,respectively.The addition of rare earth La or Ce enhanced the dispersion of Co on the catalyst surface,and increased the catalytic activity.