| 摘要 |
PROBLEM TO BE SOLVED: To obtain a catalyst exhibiting a high conversion rate and high selectivity in the fluorination of a halogenated org. compd. and to fluorinate a halogenated org. compd. with anhydrous gaseous HF in the presence of the chromium catalyst carried on a carrier. SOLUTION: The catalyst comprises an amorphous compd. of Cr (III) carried on a carrier formed from aluminum fluoride (AlF3) having a large surface area. This aluminum fluoride is available by fluorinating alumina having at least 150 m2/g specific surface area with gaseous HF at <=300 deg.C initial temp. This temp. is raised to >320 to <450 deg.C final temp. at <=100 deg.C/hr temp. gradient, the fluorination reaction is continued at the final temp. until HF is fed by a molar amt. equal to at least the stoichiometric amt. with respect to alumina, preferably 1.3 time the stoichiometric amt. and the fluorination reaction is carried out until aluminum fluoride whose fluorine content does not fall below 95% of the stoichiometric amt. is obtd.
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