The liquid-phase catalytic hydrogenation of dimethyl-nitrobenzene (DN) to Dimethyl-aniline (DA) was carried out in ethanol using 5% Pd/C as a catalyst. The effects of hydrogen partial pressure (400–1000 kPa), reaction temperature (343–403⁰K), catalyst loading (5–15 g/lit), speed of stirring range (200-800 rpm) and dimethyl-nitrobenzene concentration (0.12–0.75 mol/lit) on the hydrogenation of dimethyl-nitrobenzene and the yield of Dimethyl-aniline have been studied. Dimethyl-aniline was the only reaction product, generated through the hydrogenation of the Nitro group of dimethyl-nitrobenzene. The effects of hydrogen partial pressure, catalyst loading, dimethyl-nitrobenzene concentration and temperature on the reaction conversion have been reported. Near first-order dependence on dimethyl-nitrobenzene concentration and hydrogen pressure were observed for the initial rate of dimethyl-nitrobenzene hydrogenation over the 5% Pd/C catalyst. Conventional Arrhenius behavior was exhibited by catalyst, Pd/C showed activation energies of 614 J/mol. A simple power law model was used for analysis of the reaction kinetic data.
