| 摘要 |
Paraffins in the C4-200 DEG C. range are isomerized at at least 250 DEG C. in the presence of hydrogen and a catalyst comprising a platinum group metal, alumina and at least 1% wt. of fluorine in an amount of from 1.2X10-4 to 3.2X10-4 grams per square metre of alumina surface area. Suitable conditions are 250-500 DEG C., 0-2000 p.s.i.g., 0.05-10 v./v./hr. and a hydrogen to hydrocarbon mol. ratio of 0.01-20:1. The catalyst preferably has a surface area of at least 300 m.2/g. and is prepared by adding fluorine to a platinum alumina composite to provide up to 15% wt. of fluorine, preferably by the method described in Specification 956,684, comprising contacting the catalyst at elevated temperatures with the vapour of a fluorine compound of the formula XY2F2 in which X is carbon or sulphur and Y is hydrogen or fluorine, particularly carbon tetrafluoride. The catalyst may also contain chlorine and other refractory oxides. Specification 823,010 also is referred to. |
