NICKEL SUPPORTED ON TITANIA SILICA - PREPARATION, CHARACTERIZATION AND ACTIVITY FOR LIQUID-PHASE HYDROGENATION OF ACETOPHENONE

TiO2:SiO2 supports were prepared by impregnation of SiO2 with an n-hexane solution of titanium tetraethoxide and were used to prepare supported nickel (20% w/w) catalysts. The supports were characterised by X-ray fluorescence (XRF), BET surface area measurements, X-ray diffraction (XRD), UV-VIS diffuse reflectance spectroscopy, and transmission electron microscopy (TEM). The supported nickel catalysts were further characterised by hydrogen chemisorption, XRD, TEM, temperature-programmed reduction (TPR), and degree of reduction measurements. The catalysts were tested for liquid-phase hydrogenation of acetophenone. The TiO2:SiO2 supports were found to have good dispersion of TiO2 at lower loading but showed agglomeration at higher loadings and existed exclusively as anatase phase. Ni/TiO2:SiO2 catalysts showed strong suppression in hydrogen chemisorption similar to a Ni/TiO2 catalyst indicating strong metal support interaction (SMSI). The catalysts showed good activity for liquid-phase hydrogenation of acetophenone, which was comparable to Ni/TiO2 and greater than Ni/SiO2. Ni/7.3%TiO2:SiO2 showed a maximum in both catalytic activity and in the suppression of hydrogen chemisorption.