A catalytic process for the disproportionation of alkenes in a distillation column reactor, whereby high conversion and selectivity are simultaneously achieved.

A catalyst for the metathesis of olefins and functionalized olefins, which contains a compound having the formula B.sub.2 O.sub.3 -Re.sub.2 O.sub.7 /Al.sub.2 O.sub.3 -SiO.sub.2.

A catalyst for the metathesis of olefins and functionalized olefins, which contains a compound having the formula B.sub.2 O.sub.3 --Re.sub.2 O.sub.7 /Al.sub.2 O.sub.3 --SiO.sub.2.

A mixed olefin feedstock obtained from disproportionating C.sub.8 to C.sub.18 1-olefins can be used as such for a dimerization process to produce branched hydrocarbons that are useful as lubricating oils or greases.

Olefins are converted into other olefins having different numbers of carbon atoms by contact with a catalyst produced by contacting an inorganic refractory oxide support containing rhenium oxide with a promoting amount of at least one aluminum alkyl and, optionally, at least one tin alkyl compound under conditions suitable for aluminum and tin alkyl compounds to promote the activity of the rhenium oxide for the disproportionation reaction.