| 摘要 |
Fluorocarbons (other than fluoroform) are obtained by pyrolysing fluoroform at 500 DEG -1200 DEG C. in the presence of a catalyst comprising an activated carbon, a fluoride of a metal of Group Ia or IIa of the Periodic Table, or aluminium fluoride, this last including catalysts obtained by the fluorination of alumina and still containing oxygen. The activated carbon may be used as such, or impregnated with Group IIa metal chlorides, such as MgCl2, SrCl2 or BaCl2. Specified metal fluorides are NaF, KF, LiF, RbF, CsF, MgF2, CaF2, SrF2 and BaF2. Aluminium fluoride catalysts may be obtained by fluorinating alumina with HF, CF2Cl2, CF2ClCF2Cl, CF2ClCFCl2 or CHF3; or AlF3 may be used, as such or supported on a non-siliceous carrier such as corundum or fused beryllia or thoria. The products obtained are saturated perfluorocarbons and fluorohydrocarbons and olefinic products. In examples the main products are CF4, C2F6, C2HF5, C2F4, C3F6, C3F8, C4F8 and C4F10.ALSO:Catalysts suitable for the pyrolysis of fluoroform (see Division C2) comprise AlF3 supported on a non-siliceous carrier such as corundum or fused beryllia or thoria.
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