Selective Hydrogenation. I.para-Chloronitrobenzene topara-Chloroaniline Platinum on Carbon As Catalyst

p -Chloronitrobenzene ( p -CNB) was selectively hydrogenated to p -chloroaniline ( p -CA) using 5% Pt/C as catalyst. Using Pt/C as catalyst and with the proper choice of process conditions it was possible to obtain p -CA with 99% selectivity at a conversion level of 85%; implying that hydro-dehalogenation is minimized. The reaction was first order with respect to hydrogen and first order with respect to p -CNB. The energy of activation was 10.2 kcal/gmole.