Characterization of γ-alumina-supported manganese oxide as an incineration catalyst for trichloroethylene

Trichloroethylene (TCE) decomposition over a MnO_x/γ-Al₂O₃ catalyst in a fixed-bed reactor was conducted in this study. The MnO_x/γ-Al₂O₃ powders were prepared by the incipient wetness impregnation method with aqueous solution of manganese nitrate. The catalysts were characterized by DTA-TGA, XRD, porosity analysis, SEM, EDX, and XPS. The results show that the main distinct weight loss is found at the temperature around 373 and 873 K, the MnO peaks (2θ = 34.9° and 40.5°) are only observed crystal phase on the fresh catalyst, the SEM image of the MnO_x-impregnated γ-Al₂O₃ support is much different from the calcined catalyst, and the Mn element quantity on the catalyst surface is higher than that of the impregnated support. The products and reactants distributions from the oxidation of TCE over MnO_x/γ-Al₂O₃ were analyzed by GC. The results show that the TCE conversion starts from 5% at 443 K and rises to very high values in the 673-873 K ranges and that the CO₂ yield also pushes to 99% at the same temperature ranges. HCl and Cl₂ are the other main products with little halogenated VOC intermediates.