An active catalyst, MnO2/Al2O3, Was prepared by a novel technique as well as wet impregnation method. Total oxidation of chlorinated aromatics on supported manganese oxide catalysts was investigated. It is seen that MnO2 supported on Al2O3 is an effective catalyst for the oxidative destruction of o-DCB in the concentration range of 1611-2263 ppm at temperatures over 350 degrees C. It is also seen that for the catalyst with 0.029% MnO2, the activity per unit amount of MnO2 is much higher than that for the other catalysts and the activity per unit amount of MnO2 decreases sharply for MnO2-loading above 0.5%. This high activity may be attributed to a high degree of dispersion of MnO2 achieved by deposition from colloidal solution. No chlorinated byproducts are detected in the effluent during the oxidative destruction of o-DCB. It is proposed that catalyst with MnO2-loading less than 0.5% MnO2 can be effective for the oxidative degradation of o-DCB. Such catalysts will be less difficult to dispose of after use in view of their low heavy-metal content, and consequently, less harmful to the environment. The possibility of supporting MnO2 on clay materials may be explored and very cheap catalysts are likely to be obtained by depositing MnO2 from colloidal solutions. (C) 2008 Elsevier B.V. All rights reserved.