Heterogeneous catalytic transfer hydrogenation reactions of 4-nitrodiphenylamine

Abstract A new method for the preparation of p-phenylenediamine analogues from 4-nitrodiphenylamine by transfer hydrogenation is described here. Two catalysts used here are Raney nickel and palladium supported on carbon. A class of amines could be prepared by using different alcohols or ketones with this technique. The steric effect of alcohols plays an important part in the product yield, with the final product yield decreasing with the bulkiness of the alcohol. Atomic absorption and XPS (X-ray photoelectron spectroscopic) studies on the Raney nickel catalyst indicate that increasing aluminium content in the final catalyst by modifying the catalyst preparation conditions increases the final product yield. Palladium is found to be more active than Raney nickel for this transfer hydrogenation reaction. Both catalysts are compared by kinetics and modelling studies. The rate constants and activation energies for the reaction are determined by fitting the simulation to the experimental data.