ISSN:
1572-879X
Schlagwort(e):
AlF3 supports
;
CrF3/AlF3 catalyst
;
activity
;
reaction conditions
Quelle:
Springer Online Journal Archives 1860-2000
Thema:
Chemie und Pharmazie
Notizen:
Abstract The effect of the structure of AlF3 supports in CrF3/AlF3 catalysts and their activity were studied, and a selection of suitable reaction conditions for fluorination of trichloroethylene and HCFC-133a was made. We found that neither AlF3 (α- and γ-modifications) nor CrF3/α-AlF3 exhibits significant activity for the reaction of HF with CCl2=CHC1 or CF3CH2Cl. However, CrF3/γ-AlF3 exhibits high activity, which increases with increasing surface area and decreasing crystallite size of the γ-AlF3 support, and that dramatically affects the fiuorination of CF3CH2Cl. Investigation of a series of CrF3/γ-AlF3 catalysts shows that the turnover rates per unit of the total surface area and of the free CrF3 surface area significantly increase with increasing content of Cr3+ loading. Optimum temperature for the reaction of HF with CCl2=CHCl is 260°C, while with CF3CH2Cl it is 350°C, with flow ratios HF∶TCE = 6∶1 andHF∶HCFC-133a = 10∶1.
Materialart:
Digitale Medien
URL:
http://dx.doi.org/10.1007/BF00811495
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