Oxidative decomposition of chloropentafluoroethane (CFC-115) in the presence of methane over γ-alumina-supported metal or metal oxide catalysts

The oxidative decomposition of CFC-115 in the presence of methane was studied over γ-alumina-supported metal or metal oxide catalysts. γ-Alumina-supported zinc(II) oxide, vanadium oxide, Cr(III) and Pt catalysts showed high activity in the decomposition of CFC-115. γ-Alumina-supported chromium(III) oxide and Pt catalysts differed from the other catalyst in that the conversion of CFC-115 increased with increase in the partial pressure of methane. It is considered that water produced by the combustion of methane provided this catalytic reaction for the decomposition of CFC-115. To verify this theory, the amount of water produced by conversion of methane on γ-alumina-supported Pt catalyst was calculated. Then, corresponding amount of water was fed instead of methane and the decomposition of CFC-115 in both cases was compared. It was found that without methane the CFC-115 conversion decreased. It was concluded that methane combustion not only provides water to CFC but also provides heat to the catalysts to accelerate the decomposition of CFC.