Carbon Nanotube-Supported Iron Complex Catalyzes 1-Hexene Dimerization

Abstract

Supported catalysts for ethylene polymerization and oligomerization have gathered significant interest due to the benefits of catalyst recyclability and ease of removal from reaction media. However, reports on the oligomerization of heavy olefins remain scarce. This heterogenization process typically involves immobilizing an efficient homogeneous catalyst onto a selected support such as zeolites, silica, or metal–organic/covalent-organic frameworks. Carbon nanotubes (CNTs) present a promising support platform due to their high mechanical strength and low solubility in organic solvents. In this study, we report the heterogenization of a pyridine bis-imine iron complex on CNTs and its activity in the dimerization of 1-hexene. The CNT/iron complex was synthesized using imido linkage and characterized by TEM/EDS and inductively coupled plasma–optical emission spectroscopy to determine the distribution and loading of the catalyst. An optimal iron/CNT ratio of 1:1 by weight was identified. The system exhibited high reactivity in the dimerization of 1-hexene, achieving 94% olefin consumption and 64% C12 formation. Characterization of the resulting oligomers indicated that the CNT-supported catalyst operates via a mechanism similar to that of the homogeneous catalyst.