Fatty acid methyl ester heterogeneous self‐metathesis in hydrophobic green solvent: Mass transfer limitations, catalyst recyclability, and stability

Abstract

The role of room-temperature ionic liquids (RTILs), [bmim] [PF 6 ] and [bmim][Tf 2 N], as reaction media regarding the catalytic activity and stability of methyltrioxorhenium (MTO) supported on ZnCl 2 -modified mesoporous Al 2 O 3 has been studied for self-metathesis of a functionalized olefin, methyl oleate. The humidity influence on the catalytic activity was probed. The catalyst recycling ability and the kinetics of the metathesis reaction using these RTILs were also investigated. It was found that the MTO-based catalyst was efficient in viscous hydrophobic RTIL solvents. However, their high viscosity was found to increase the mass transfer limitations thus somewhat impacting the reaction kinetics. Nevertheless, better catalyst stability was reached allowing its possible recycling when used in RTIL media.

Self-Metathesis of Methyl Oleate Using Ru-NHC Complexes: A Kinetic Study

“…The objectives were to compare the activity, selectivity, and stability of the catalysts but scarcely to go into kinetic data interpretation. Some kinetic studies using methyl oleate (Z-methyl 9-octadecenoate) were nevertheless performed [12,13] but they did not concern Ru catalysts. The mechanism of the metathesis reaction has been extensively studied, involving several consecutive steps: an initiation (reverse reaction) that transforms part of the pre-catalysts into catalytic active species, a propagation step being the catalytic cycle itself, and a recombination step that restores the pre-catalytic species.…”