Catalytic combustion of chlorobenzene on Pt/γ-Al2O3 in the presence of aliphatic hydrocarbons

During the catalytic combustion of chlorobenzene on a 2% Pt/gamma-Al2O3 catalyst, considerable amounts of polychlorinated benzenes an formed as by-products. The co-feeding of heptane practically eliminates this unwanted side-reaction. Moreover, the conversion of chlorobenzene occurs at much lower temperatures (the T-50% drops from 305 to 225 degrees C). Simultaneously, the conversion of heptane is retarded. The addition of other hydrocarbons have a similar effect. Water and heat produced by the combustion of the added hydrocarbon cannot explain the increase in destruction rate of chlorobenzene. Removal of Cl from the surface by the alkane appears to be the ruling factor. (C) 1999 Elsevier Science B.V. All rights reserved.