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, (La0.84,Sr0.16)(Mn0.67,Co0.33)O3) at reaction temperatures above 550°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.