Perovskite-type oxides - catalysts for the total oxidation of chlorinated hydrocarbons

Chloromethane, dichloromethane and 1,2-dichloroethane were completely decomposed in air on perovskite-type catalysts (LaMnO3, LaCoO3, (La0.84Sr0.16)(Mn-0.67,Co-0.33)O-3) at reaction temperatures above 550 degrees C. Besides the main reaction products (carbon dioxide, water and hydrochloric acid), by-products (higher chlorinated-, C-C coupling- and cracking products) were formed in the low temperature range. Depending on the reaction temperature, residence time and kind of chlorinated hydrocarbon a reversible catalyst deactivation takes place. In the case of LaCoO3 catalysts an irreversible deactivation was observed. X-ray diffraction (XRD) and electron probe microanalysis (EPMA) measurements with the perovskite-type catalysts after interaction of chlorinated hydrocarbons indicate the formation of chlorinated species on the catalyst surface and in the bulk. (C) 1998 Elsevier Science B.V. All rights reserved.