Liquid-phase hydrogenation of o-chloronitrobenzene over supported nickel catalysts

The effect of supports (SiO2, ZrO2, TiO2 and Al2O3) on the performance of nickel catalysts for the hydrogenation of o-chloronitrobenzene was investigated. It was found that the supports strongly influenced the catalytic performance of the catalysts, and Ni/TiO2 showed the best catalytic performance. Over Ni/TiO2, 99.9% conversion of o-chloronitrobenzene and 99.5% selectivity of o-chloroaniline were obtained at 1.5 MPa and 363 K. The good performance of Ni/TiO2 was perhaps attributed to the strong polarization of NO band induced by oxygen vacancies of TiOx which was produced by a high temperature reduction, and the NO band polarized was attacked easily by hydrogen dissociatively adsorbed on the nickel particles.