Promoting action of water on slurry phase hydrogenation of p-nitrotoluene on raney nickel

Enhancement in the reaction rate of hydrogenation of p ‐nitrotoluene on Raney nickel in a three‐phase slurry reactor due to the presence of water in the reaction mixture has been observed. The promoting action was found to be dependent on the initial concentration of water, the reaction rate passed through a maximum when the initial water concentration varied from 0.0 to 10.85 (mmol cm ‐3 ). A two to three fold increase in the reaction rate dependent on the temperature has been observed at the optimum water concentration. However, at very high concentrations (above 8.0 mmol cm‐ 3 ) water inhibited the hydrogenation. The reaction is not influenced significantly by the presence of p ‐toluidine.