Design de líquidos iônicos para conversão de CO2

Abstract

The acceptance that climate change is direct related to increasing greenhouse gas emissions, carbon dioxide (CO2) in particular, and the need to improve synthesis with reusable inputs are some of the current concerns. Thus, this thesis aims to contribute to the development of new catalytic materials for the processes that explore the possibilities of production of organic carbonates from CO2. Cyclic carbonates have several applications. Furthermore, their production from CO2 would represent a huge step towards mitigating environmental impacts. For this, new ionic liquids (ILs) of imidazolium ([bmim+]) and tetra-n-alkylammonium ([TBA+]) cations with anions derived from surfactant salts ([C12SO4-], [C12ESO4-], [C12BSO3-], [C12SAR-]) were synthesized and tested as catalysts of different cycloaddition of CO2 in epoxides. ILs were characterized by FTIR, 1H-NMR, TGA and DSC. The [Cl-], [Na+] and moisture residues determined the purity of the material. The ILs showed good activity in propylene carbonate (PC) synthesis, 79.2% of conversion and 87.7% of selectivity when [TBA][C12SO4] was used. For this reaction, catalyst kept its activity for at least 5 cycles. In the synthesis of styrene carbonate (SC), [TBA] [C12BSO3] was the most efficient IL reaching 81.4% of conversion and 87.0% of selectivity. This IL also showed significant activity in the synthesis of glycidyl isopropyl ether carbonate (GC) and epichlorohydrin carbonate (EC)