Isomerization catalyst and process

A process for isomerizing a mixture of olefins containing about 8-24 carbon atoms, said mixture of olefins comprising 50 to 95 weight percent of vinyl olefins and 5 to 50 weight percent of vinylidene olefins, said process comprising heating said mixture of olefins while in contact with a catalytic amount of a catalyst mixture formed by controlled oxidation of aluminum trialkyl in an inert atmosphere and in the presence of a cobalt (II) salt of an organic carboxylic acid so that the aluminum trialkyl is converted into an aluminum compound of the formula R.sup.3.sub.n Al(OR.sup.4)p where R.sup.3 and R.sup.4 are the same or different and are alkyl, n is an integer from 0.75 to 2.25, and p is an integer from 0.75 to 2.25, the sum of n and p being 3, said controlled oxidation being performed in situ using oxygen present in the cobalt salt, said heating of said mixture of olefins being conducted at a temperature of about 160.degree. C. to 180.degree. C. to effect isomerization of vinyl olefin to internal olefin.