Low-temperature deep oxidation of dichloromethane and trichloroethylene by H-ZSM-5-supported manganese oxide catalysts

The catalytic activity and selectivity of a series of H-ZSM-5-supported manganese oxide catalysts with various manganese content, namely 1.0, 4.3, and 8.3 wt%, were evaluated for the oxidation of dichloromethane (DCM) and trichloroethylene (TCE). Previously, the highly active performance of H-ZSM-5 zeolite with respect to other supports, such as alumina and silica, was demonstrated, pointing out that the acidic properties of the support along with a high metallic dispersion of the resultant catalyst were key factors conditioning the catalytic performance. Mn(4.3%)/H-ZSM-5 catalyst was found to be an optimum catalyst for the combustion of both single and double carbon chlorinated compounds achieving > 95% conversion levels at temperatures between 400 and 450 degreesC. The major oxidation products were carbon monoxide, carbon dioxide, hydrogen chloride, and chlorine. It was observed that high manganese loadings led to increasing amounts of carbon dioxide and chlorine. (C) 2003 Elsevier Inc. All rights reserved.