Anatase supported nickel nanoparticles for catalytic hydrogenation of 4-nitrophenol

Nickel nanoparticles supported on titania were prepared by a combined sol-gel and chemical reduction procedure. XRD reveals face centred cubic structure of nickel nanoparticles; while tetragonal anatase type structure for the supporting titania phase. The structural and morphological properties showed well dispersion of nickel nanoparticles on the supported titania lattice. From TEM images, the average crystallite size of nickel nanoparticles was found to be similar to 20 nm. HRTEM images identified lattice fringes with spacing around 0.203 nm, which matches with 'd' value for the (1 1 1) plane of cubic nickel. The saturation magnetization, remanent magnetization, and coercivity values of supported nickel/bare nickel nanoparticles were higher than that of bulk nickel. This enhanced magnetization property was helpful for its separation from the reaction mixture by magnetic field. The influence of titania support on the performance of nickel catalysts for the hydrogenation of 4-nitrophenol was investigated. The catalytic performance was higher for supported nickel nanoparticles as compared to that of bare nickel nanoparticles. Supported nickel catalyst was found to be superior, cost effective, magnetically separable and recyclable in hydrogenation reactions. (C) 2014 Elsevier B.V. All rights reserved.