Liquid-Phase Catalytic Hydrogenation of p-Chlorobenzophenone to p-Chlorobenzhydrol over a 5 % Pd/C Catalyst

摘要

The kinetics of the liquid-phase catalytic hydrogenation of p-chlorobenzophenone have been investigated over a 5 % Pd/C catalyst.The effects of hydrogen partial pressure (800-2200 kPa),catalyst loading (0.4-1.6 gm dm~(-3)),p-chlorobenzophenone concentration (0.37-1.5 mol dm~(-3)),and temperature (303-313 K)were studied.A stirring speed > 20 rps has no effect on the initial rate of reaction.Effects of various catalysts (Pd/C,Pd/BaSO_4,Pd/CaCO_3,Pt/C,Raney nickel)and solvents (2-propa-nol,methanol,dimethylformamide,toluene,xylene,hexane)on the hydrogenation of p-chlorobenzophenone were also investigated.The reaction was found to be first order with respect to hydrogen partial pressure and catalyst loading,and zero order with respect to p-chlorobenzophenone concentration.Several Langmuir-Hinshelwood type models were considered and the experimental data fitted to a model involving reaction between adsorbed p-chlorobenzophenone and hydrogen in the liquid phase.