| 摘要 |
CASE 3421 "SUPERACIDIC CATALYST AND PROCESS FOR PREPARING IT" A superacidic catalyst, sulfated metal oxide, is obtained by means of a process comprising: (i) hydrolysing a water-soluble compound, capable of being hydrolysed in a water-alkaline medium, of tetravalent zirconium, hafnium or titanium, in order to precipitate a hydrous metal oxide in gel form; (ii) drying said gel at a temperature comprised within the range of from 150.degree.C to 300.degree.C, in order to obtain a catalyst support; (iii) impregnating said support by means of a sulfating agent selected from aqueous sulfuric acid or aqueous solution of a sulfate salt; (iv) drying said impregnated support and calcining it in an oxidizing atmosphere, at a temperature comprised within the range of from 400.degree.C to 700.degree.C. According to a particular form of practical embodiment, the support obtained from step (iii) is treated with a noble metal compound before bring submitted to the end calcination.
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