Heterogeneous catalytic degradation of chlorofluoromethanes on zinc oxide surfaces

Abstract

Abstract The decomposition of the spray propellants CFCl 3 and CF 2 Cl 2 on the surface of variously treated zinc oxides has been studied by X‐ray photoelectron spectroscopy. Whereas decomposition on “untreated” surfaces could only be induced photolytically ( λ < 400 nm) “activated” surfaces caused both spontaneous dark and additionally, photocatalytic decomposition. Indications are that the mechanism involves interaction between physisorbed substrate molecules and surface electrons of the catalyst. Decomposition causes chlorination of the zinc oxide resulting in a surface approaching hypochlorite‐perchlorate stochiometry.