PURPOSE: To exchange, with high activity and high selectivity, a halogen other than fluorine for fluorine in organic compounds, by using hydrogen fluoride in the presence of a Cr-free catalyst system comprising a bismuth/alkaline earth metal catalyst in a specific atomic ratio and a lanthanide compound catalyst.
CONSTITUTION: A Cr-free catalyst comprising a bismuth/alkaline earth metal catalyst containing 0.005-0.8 g atom of bismuth per mol of the alkaline earth metal, especially 0.008-0.7 g atom and at least one lanthanide compound catalyst (it may contain a carrier) is used in exchange of halogen other than fluorine for fluorine in organic compounds by means of hydrogen fluoride, especially exchange of chlorine for fluorine. As the lanthanide catalyst are exemplified cerium, lanthanum and dysprosium, and they are used preferably in 2-30 wt.%. The catalyst may be supported on a carrier such as Al2O3, AlF3, active carbon, etc. The catalyst is free from Cr, which is desirable to environment.
RUDORUFU BURAADEN
