Homogeneous and Heterogeneous Ionic Liquid System: Promising “Ideal Catalysts” for the Fixation of CO₂ into Cyclic Carbonates

Abstract

Scheme 1. The synthesis of cyclic carbonates via CO 2 cycloaddition reaction with epoxides catalyzed by ILCs.

Emerging Ionic Polymers for CO

“…Recent reviews have focussed on the design of and progress around ionic polymers for the CO 2 cycloaddition reaction, [14,16,18,21,22] with minor mentions of poly(ionic liquid)s or ionic polymers. To our knowledge, only one review focussed only on imidazolium-functionalized ionic polymers as heterogeneous catalysts, only partially addressing the subject reviewed here.…”

“…[18,49] POPs include HCPs, porous aromatic frameworks (PAFs), porous polymer networks (PPNs), conjugated microporous polymers (CMPs), COFs, and covalent triazine frameworks (CTFs). [14] Furthermore, the functionalization of POPs with nitrogen-containing groups (e.g. amines, imines, triazines, carbazoles, imidazoles, and azo linkages) has been shown to increase CO 2 capture and conversion abilities.…”

“…amines, imines, triazines, carbazoles, imidazoles, and azo linkages) has been shown to increase CO 2 capture and conversion abilities. [14] Porous ionic polymers (PIPs) are a class of POPs that have controllable porous structures, abundant ionic sites, good ion exchange properties, and tuneable chemical functionalities. [50] In particular, halogen-based PIPs have better CO 2 capture ability due to the strong dipole-quadrupole interactions of their ionic moieties with CO 2 .…”

“…1), in a complete atom economy reaction that meets the criteria of green chemistry. [12][13][14] Cyclic carbonates are of particular interest in applications such as aprotic polar solvents and electrolytes in secondary batteries, precursors for polycarbonate and polymeric materials synthesis, and intermediates in the production of value-added chemicals such as dialkylcarbonates, glycols, carbamates, pyrimidines, and purines. [13,15,16] The use of a catalyst in this reaction is essential for reducing the temperature and the pressure to make it efficient and economically viable.…”

A Study on the Stability of Carbon Nanoforms–Polyimidazolium Network Hybrids in the Conversion of CO2 into Cyclic Carbonates: Increase in Catalytic Activity after Reuse

“…Recently, we have exploited the well-known high affinity between ionic liquids (ILs) and CNFs [ 25 ] by functionalizing CNTs and CNHs with imidazolium salt-based polymers, which perfectly covered the whole surface of the carbonaceous skeletons [ 26 , 27 , 28 ]. Among the numerous applications of ILs, their use for the uptake of CO 2 and its conversion has aroused a great interest in the scientific community [ 29 , 30 ]. In this context, we have focused part of our research in the development of different imidazolium-based catalysts for the transformation of CO 2 to value-added products [ 26 , 31 , 32 , 33 , 34 ].…”