Properties of chromium (III) oxides involved in the catalytic gas phase fluorination of CF3CH2Cl

Abstract The fluorination of chromium oxides reduces the chromium specieson the surface. A low fluorination by HF does not modify the totalamount of reversibly oxidizable chromium sites, but increases thestrength of these sites. Mobile dioxygen (measured by isotopicexchange) was required to obtain a good fluorination activity.These dioxygen species would be exchanged by HF which is probably active in the fluorination of CF 3 CH 2 Cl and would prevent the irreversibly catalyst fluorination.