| abstract |
n-Butenes can be converted catalytically into isobutene if a mixture, which contains at least one n-butene and hydrogen, is brought into contact, at a temperature of from 400 to 600 DEG C and a residence time of from 1 to 10 seconds, with a specially activated Al2O3 catalyst doped with halogen compounds of elements of the 3rd to 5th main group and 2nd to 8th subgroup of the Periodic Table of the Elements and/or with hydrohalic acids, the special activation consisting in an aluminium hydroxide or aluminium oxide hydrate with a content of volatile ammonium salts being calcined, prior to doping, to give Al2O3, said volatile ammonium salts being driven off. |