SELECTIVE ISOMERIZATION OF BUTENE TO ISOBUTENE

Selective isomerization of butene to iso-butene has been studied with pure and variously modified alumina as catalysts. Results can be self- consistently explained by concluding that (i) the monomolecular mechan ism operates and requires Lewis acid sites, the presence and quality o f which can be modulated by heat treatment in hydrogen, by surface mod ification with halogens, and by application of certain catalytic poiso ns, and (ii) the bimolecular mechanism is related to the Bronsted acid sites and is stimulated, as expected, by increased pressure of n-bute ne. (C) 1994 Academic Press, Inc.