(676c) Olefin Oligomerization on Carbon Supported Cobalt Catalyst: Identification of the Reaction Pathway

In this presentation we will discuss the reaction pathway involved in oligomerization of liquid 1-butene to linear octenes (in 70-85% selectivity) using carbon supported cobalt. The liquid products were characterized by 2 dimensional GCMS which allowed us to better understand the complicated reaction pathway occurring with this catalyst. The linear octene products decreased in selectivity according to 3-octene > trans-2-octene> cis-2-octene > 4-octene. Methyl-heptenes including trans/cis-5-methyl-2-heptene > trans/cis-5-methyl-3-heptene > trans-3-methyl-2-heptene (at the lowest conversion) were the other major products. The product distribution suggests the reaction pathway involves a head- to -head coupling of two 1-butene molecules to form internal linear octenes. Head- to -tail coupling of two 1-butene molecules or a coupling between 1-butene and 2-butene forms the observed methyl-heptenes. The rate of head- to -head coupling is higher than the rate of head- to -tail or the rate of 1-butene to 2-butene coupling as indicated by the higher selectivity of linear octenes. We will then compare the reaction pathway of this catalyst for 1-butene conversion to the conversion of other olefins to obtain a better mechanistic understanding of this catalyst system.