Decomposition of chlorofluorocarbons in the presence of water over zeolite catalyst

Abstract The decomposition of chlorofluorocarbons (CFCs) in the presence of water was examined over a variety of solid acid catalysts. More than 40% of the conversion of CFC was observed on HY zeolite, H-mordenite, H-ZSM-5, γ-Al 2 O 3 , and SiO 2 TiO 2 catalysts, and the selectivity to CO and CO 2 was nearly 100% except on γ-Al 2 O 3 . Although the H-mordenite had the highest activity among the tested catalysts, it was gradually deactivated during the reaction due to the elimination of Al atoms from the zeolite framework. A good relationship was found between the reactivity on H-mordenite and the bond energy of C Cl in compounds of CCl 4 , CCl 3 F, CCl 2 F 2 , and CClF 3 , suggesting that the rate controlling step was the cleavage of the C Cl bond.