In this review, the most relevant aspects of skeletal isomerization of
n-butene to isobutene are discussed: the nature of the active sites,
the prevailing mechanism of the skeletal isomerization, and the relati
on of this to that of n-butane. It is concluded that the prevailing me
chanism of skeletal isomerization ofn-butene is monomolecular (in cont
rast to butane isomerization) and requires Bronsted acid (OH) active s
ites. The selectivity and catalytic stability can be influenced by the
shape selectivity of zeolites and zeotypes. These effects are explain
ed on the basis of the knowledge on the prevailing mechanism.