“…On one hand, catalysts effective for the decomposition of halogen-containing compounds such as chlorofluorocarbons (CFCs), hydrofluorocarbons (HFC), and perfluorocarbons (PFC) have been studied by many researchers. A number of metal oxide catalysts including γ-Al 2 O 3 ; − SiO 2 −Al 2 O 3 ; TiO 2 −SiO 2 ; ZrO 2 −Cr 2 O 3 ; ZnO/γ-Al 2 O 3 , V 2 O 5 /γ-Al 2 O 3 , and Cr 2 O 3 /γ-Al 2 O 3 ; , WO 3 /Al 2 O 3 −ZrO 2 ; , WO 3 /M x O y (M = Ti, Sn, Fe); TiO 2 −ZrO 2 ; Al−metal oxides; mixed oxides of MnO−CuO; ZrO 2 /FeCl 3 /activated charcoal; , various zeolites including H−Y, ,− Na−Y, , H−mordenite, , Y−FAU, H−ZSM5, CsNaY−FAU, and supported noble metals; Au/Co 3 O 4 ; and Pt/TiO 2 −ZrO 2 mixed oxides were studied. Special catalysts such as CuO/CuSO 4 , , H 2 SO 4 /TiO 2 and H 2 SO 4 /TiO 2 −ZrO 2 , transition metal chloride promoted γ-Al 2 O 3 , and BPO 4 − are also reported.…”