Not all acid sites are created equal: Alkene isomerization and dimerization occur on separate sites on Amberlyst®15 catalyst

Linear 1‐alkenes undergo concurrent dimerization and double bond isomerization on the solid acid catalyst Amberlyst®15. Kinetic data show that double bond isomerization occurs on a site where the alkene adsorption coefficient is small, whereas alkene dimerization occurs on a site where the alkene adsorption coefficient is large. The fraction of isomerization sites occupied by alkene is small, whereas the dimerization sites are practically saturated with alkene. Logically, two different types of acid sites must exist on the surface of Amberlyst®15 catalyst. On the dimerization sites, substantial skeletal rearrangement occurs, likely via rapidly isomerizing carbenium ions, π‐complexes, and/or protonated cyclopropyl intermediates. Stereochemical environments of sulfonic acid groups strongly affect alkene adsorption behavior and reactivity.