Catalytic composition comprising nickel and a phosphine-type ligand, and use thereof in an olefin oligomerisation method

摘要

A process for the dimerization of ethylene to 1-butene, carried out with a catalytic composition comprising: at least one nickel precursor with an oxidation number of (+II), at least one phosphine ligand with formula PR₁R₂R₃ in which the groups R₁, R₂ and R₃ may be identical or different and which may or may not be bonded together, and at least one activating agent selected from the group formed by chlorinated and brominated hydrocarbylaluminium compounds, used alone or as a mixture, the composition having a molar ratio of the phosphine ligand to the nickel precursor in the range 5 to 30 and a molar ratio of the activating agent to the phosphine ligand greater than or equal to 1.