KINETICS OF THE CATALYTIC-HYDROGENATION OF 2,4-DINITROTOLUENE .1. EXPERIMENTS, REACTION SCHEME, AND CATALYST ACTIVITY

There is a great need for quantitative data of a complex reaction network that can be used to evaluate reactor performance and selectivity in heterogeneous reactors. To this end, the chemistry and the kinetics of the catalytic hydrogenation of 2,4-dinitrotoluene over a 5% Pd/C catalyst in methanol have been studied in a batch slurry reactor at isothermal and isobaric conditions, in the temperature range 308-357 K and at hydrogen pressures ranging up to 4 MPa. The relevant reacting species have been characterized and analyzed quantitatively. A reaction scheme is proposed with two parallel pathways and three stable intermediates. During a short induction period at the initial stage of the reaction, a rapid deactivation of the catalyst has been observed. It has been shown experimentally that exposure of the catalyst to oxygen and hydrogen plays an important role in this effect. For the five identified main reactions, the quantitative kinetic data will be given in another article. © 1990, American Chemical Society. All rights reserved.