Combustion of trichloroethylene and dichloromethane over protonic zeolites: Influence of adsorption properties on the catalytic performance

Abstract

The deep oxidation of dichloromethane (DCM) and trichloroethylene (TCE) over protonic zeolites (HA, HX, HY and H-ZSM-5) was studied in this work. Experiments were performed in dry air in the range 50–650 °C in a pulsed microreactor. Catalytic activity was correlated with the capacity of adsorption of DCM and TCE as well as the strength and specificity of these interactions, which parameters were determined by inverse gas chromatography (IGC). DCM is oxidized at lower temperatures than TCE, and at the same time, the interaction of this compound over the catalysts is also stronger than that of TCE. The increase of the TCE conversion in presence of the catalysts was very low, whereas these materials (specially the HY and H-ZSM-5 zeolites) have important catalytic activity for DCM oxidation. The best performance of these zeolites has been attributed to the higher density of strong acid sites, which act as active sites both in the adsorption of hydrocarbon and catalytic activation of hydrocarbon halides. The product distribution is also discussed in this work.