P-nitrophenol hydrogenation over a novel Ni/TiO₂ catalyst

A nano-sized nickel catalyst supported on mesoporous TiCh whisker, Ni/TiO₂, was prepared by incipient impregnation using Ni(NO₃)₂-6H₂O solution. The physical and reduction characters of the Ni/TiO₂ catalyst were measured by scanning electron microscopy, X-ray diffraction, N₂ adsorption, thermogravimetric analysis, and temperature-programmed reduction, and its catalytic activity was investigated by p-nitrophenol hydrogenation. The results indicated that the catalyst possessed whisker morphology, high crystallinity anatase phase, high specific surface area, and mesostructure. It also showed high activity and stability. The conversion of p-nitrophenol over Ni/TiO₂ increased with increasing nickel loading. When the nickel loading was over 10%, the catalyst activity and selectivity changed little. The 10%Ni/TiO₂ catalyst calcined at 500°C and reduced at 450°C showed the best catalytic performance. The catalytic activity of Ni/TiO₂ was four times higher than that of the commercial Raney nickel. No obvious deactivation of the catalyst was observed after repeated using seven times.