- Catalytic fluorination of 1,1,1-trifluoro-2-chloro-ethane in the presence of oxygen over chromium based catalyst doped or not by zinc supported over partially fluorinated alumina
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The addition of zinc in low amount to chromium based catalyst supported over partially fluorinated alumina has a positive effect for the fluorination reaction of CF3CH2Cl in the presence of dioxygen in order to prevent the catalyst deactivation. However, under these operating conditions, the Deacon reaction by reaction with HCl produced by Cl/F exchanges could be involved. The formation of various by-products was observed corresponding to the addition of HCl or Cl2 into halogenated double bonds.
- Loustaunau,Fayolle-Romelaer,Celerier,Brunet
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experimental part
p. 1262 - 1265
(2011/12/21)
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- Heterogeneous catalyzed synthesis of 1,1,1,2-tetrafluoroethane from 1,1,1,2-tetrachloroethane - thermodynamics and reaction pathways
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1,1,1,2-Tetrachloroethane and its fluorinated derivatives, as well as trichloroethene, were fluorinated by hydrogen fluoride in the presence of a preconditioned chromia catalyst.The reaction pathways were derived under different conditions.Fluorinated haloalkanes are formed both by dehydrochlorination/hydrofluorination mechanisms as well as a chlorine/fluorine exchange mechanism.Thus, beside fluorinated alkanes considerable amounts of halo-olefins occur in the product mixture.A survey is given of the reaction pathways showing their dependence on the reaction conditions.These are discussed with respect to the calculated thermodynamic data. - Keywords: Heterogenous catalysis; Chlorofluorocarbon; Hydrofluorocarbon; Halocarbon; Fluorination; HFC-134a formation
- Kohne, A.,Kemnitz, E.
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p. 103 - 110
(2007/10/03)
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