Hydrodechlorination of chlorinated benzenes in a continuous microwave reactor

An expeditious hydrodechlorination of chlorobenzenes is observed over 0.5% Pd/Al2O3 catalyst by conducting the reaction under microwave irradiation conditions. Even though the loss of active metal surface area is substantial and identical in both microwave and conventional heating reactions, the higher rate and sustainability of the microwave reaction may be due to the selective and rapid absorption of microwaves by the polar chlorinated substrates that facilitates their relatively easy removal from the catalyst surface. It is also speculated that the rate of desorption of the products (especially the poisonous HCl) is more critical in sustaining the catalyst activity. The experiments also reveal a significant reduction in power consumption under the microwave reaction than the reaction conducted using conventional heating.