Carbon dioxide capture by absorption into solvents comprising sterically hindered frustrated Lewis pairs

Today, there are many scientific studies to reduce the amount of carbon dioxide (CO2) emission in the atmosphere which has become a common problem of humanity with the rapidly increasing technological and industrial activities. Although the most common methods used in these studies are considered as aqueous amine solutions, it is aimed to develop new CO2 capture processes due to their high energy requirement, corrosive properties and low CO2 selectivity. In this thesis, solvents formed with sterically hindered Lewis pairs (FLP), which is a completely new approach in CO2 capture studies, are used. Although the use of FLP structures for CO2 capture processes has been theoretically proposed in recent years, the kinetic data of these reactions are not yet available in the literature. Within the scope of this thesis, sterically hindered Lewis acid chlorobis (pentafluorophenyl) borane (B (C6F5) 2Cl), synthesized by Hacettepe University Department of Chemistry, was first combined with steric hindered Lewis base Tri-tert-butylphosphine (tBu3P). The hindered Lewis pair tBu3PB (C6F5)2Cl was formed. The kinetic data of the reaction of Lewis obtained by sterically hindered Lewis couple with CO2 in bromobenzene medium at 3 different concentrations and 6 different temperature conditions were examined in detail by stop-flow technique. Since the reaction rate of the sterically hindered Lewis pair with CO2 in bromobenzene medium is very low, 3 different hybrid FLP systems react with CO2 under similar conditions using aminoethyl piperazine (AEPZ), carbonic anhydrase (CA) and bis (trifluoromethylsulfonyl) imide ([absorption] Tf2N). and kinetic data were evaluated comparatively. A new FLP structure was prepared with commercially available sterically hindered Lewis acid Tris (pentafluorophenyl) borane (B(C6F5)3) as an alternative to the sterically hindered Lewis pair which was not commercially available and the data obtained by reaction with CO2 were compared. n the last part of the study, FLP structures with commercial acid were prepared in tert-butyl methyl ether (MTBE) and cyclo-phenyl methyl ether (CPME) as an alternative to bromobenzene medium and the kinetics of the reactions performed with CO2 were compared with the previous systems.