Oligomerization of Ethylene Catalyzed by Iron and Cobalt in Organoaluminate Dialkylimidazolium Ionic Liquids

Abstract

Cationic iron and cobalt acetonitrile cationic complexes were prepared and used as catalyst precursors in catalytic ethylene oligomerization. The effects of temperature and the nature and effects of the co-catalysts were evaluated. The iron and cobalt catalysts are less active, giving turnover frequencies of 20,000 to 30,000 h -1 while the corresponding nickel analogs exhibit turnover frequencies of 215,000 h -1 . The iron and cobalt catalysts were more selective for the synthesis of 1-butene, especially at lower temperatures, compared to the nickel catalyst.

The Use of Ionic Liquids in the Oligomerization of Alkenes

“…one order of magnitude lower in chloroaluminate ILs than the analogous nickel catalyst in ethene oligomerization. [43] At the same time, they exerted higher dimer selectivity (in the range of 79-100% for iron and 66-99% for cobalt) than the nickel derivative (43-68%) and excellent selectivity for 1-butene (up to 100% and 99% within the dimer fraction for the iron and cobalt complex, respectively.) FeCl 2 and CoCl 2 turned out to be more active but the absence of ligands resulted in considerably lower selectivity to α-olefins.…”

Bioethanol as a potential eco‐friendlier feedstock for catalytic production of fuels and petrochemicals

“…The problems associated with catalyst separation from oligomerization products, as well as the difficulty of reusing transition metal catalysts, are major drawbacks of these catalyst systems. To overcome these drawbacks, a thorough study has been carried out recently to develop olefin oligomerization techniques that include the involvement of ionic liquids 189‐191 . This necessitates the utilization of transition metal (including Ti, Zr) precursor complexes having ionic liquid‐type ligands in their coordination spheres.…”

“…To overcome these drawbacks, a thorough study has been carried out recently to develop olefin oligomerization techniques that include the involvement of ionic liquids. [189][190][191] This necessitates the utilization of transition metal (including Ti, Zr) precursor complexes having ionic liquid-type ligands in their coordination spheres. They operate as reusable heterogeneous oligomerization catalysts when paired with aluminium-organic activators and can be used in different solvents such as molecular organic and ionic liquid solvents.…”

Research progress of iron-based catalysts for selective oligomerization of ethylene

“…Based on a large number of experimental studies, it indicates that the experimental effect of the catalyst supported by the carrier in the process of ethylene oligomerization is mainly affected by three factors including temperature, [123][124][125][126] concentration 127,128 and the pore diameter of the carrier. [129][130][131] In the polymerization reaction or oligomerization reaction of olen, catalysts are supported in two main ways.…”