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

Chloromethane, dichloromethane and 1,2-dichloroethane were completely decom posed in air on perovskite-type catalysts (LaMnO3, LaCoO3, (La0.84Sr0.16)(M n-0.67,Co-0.33)O-3) at reaction temperatures above 550 degrees C. Besides t he main reaction products (carbon dioxide, water and hydrochloric acid), by -products (higher chlorinated-, C-C coupling- and cracking products) were f ormed in the low temperature range. Depending on the reaction temperature, residence time and kind of chlorinated hydrocarbon a reversible catalyst de activation takes place. In the case of LaCoO3 catalysts an irreversible dea ctivation was observed. X-ray diffraction (XRD) and electron probe microana lysis (EPMA) measurements with the perovskite-type catalysts after interact ion of chlorinated hydrocarbons indicate the formation of chlorinated speci es on the catalyst surface and in the bulk. (C) 1998 Elsevier Science B.V. All rights reserved.