Metalloporphyrin Polymers with Intercalated Ionic Liquids for Synergistic CO₂ Fixation via Cyclic Carbonate Production

Abstract

Multifunctionalization of organic polymers for acting synergistically on substrate is of wide interest in the field of modern catalysis, but it is still a significant challenge. Herein, two novel bifunctional polymers were first designed and synthesized by combining ionic liquids (ILs) with zinc(II) porphyrin through simple and reversible Schiff base reactions. The fabricated polymers with flexible structures and nitrogen-rich environments presented high affinity toward CO 2 molecules at ambient conditions. Owing to the cooperative nature of intercalated ILs and Lewis acidic metal sites, these materials could serve as efficient heterogeneous catalysts for the insertion of CO 2 into epoxides to produce cyclic carbonates. As expected, these polymers exhibited good catalytic performance, robust constancy, excellent recyclability, and good substrate expansibility for this reaction in the absence of cocatalyst under mild or even ambient conditions. Notably, the selected catalyst SYSU-Zn@IL2 could directly convert diluted CO 2 (15% CO 2 in N 2 ) into cyclic carbonate at 80 °C and 3.0 MPa, further offering the great application potential for recycling real-world carbon resource.

Efficient chemical fixation and defixation cycle of carbon dioxide under ambient conditions

“…In particular, synthesis of therapeutically cherished and synthetically convenient five-membered cyclic urethanes such as oxazolidinones via cycloaddition of CO 2 with aziridines has become one of the most promising approaches in this area, because this process possess 100% atom efficiency, which exactly matches one of the most substantial criteria of green chemistry [27][28][29][30][31] . Despite being an admirable strategy to chemically capture and recycle CO 2 , most of these protocols suffer from high energy demand and utilize costly catalysts/ionic liquids to achieve ambient or near ambient condition for CO 2 fixation, even from highly enriched CO 2 source [32][33][34][35][36][37][38][39][40] . However, emissions from thermal power plants contain numerous gaseous components like SO 2 , NO 2 along with CO 2 41 .…”

Recent Advances on Imidazolium‐Functionalized Organic Cationic Polymers for CO2 Adsorption and Simultaneous Conversion into Cyclic Carbonates

“…In spite of the very low BET surface area (<10 m 2 g −1 ) and moderate CO 2 capture capacities (1.45 mmol g −1 , 273 K) of FIP‐IM, this cationic polymeric material still exhibited high activity for metal‐, solvent‐, and additive‐free synthesis of cyclic carbonates from CO 2 and epoxides under mild conditions (80 °C, 1.0 MPa) due to the presence of abundant phenolic hydroxyl groups and high density of imidazolium‐type ionic sites in the architectures . Analogously, the imine‐linker Zn(porphyrin)‐based cationic polymer with intercalated imidazolium‐based ILs (SYSU‐Zn@IL), prepared from zinc(II) tetrakis(4′‐aminophenyl)porphyin, also served as an efficient heterogeneous catalyst for the CO 2 reaction with epoxides to produce cyclic carbonates under mild conditions . Notably, SYSU‐Zn@IL with moderate CO 2 adsorption ability (1.36 mmol g −1 , 273 K) could directly convert diluted CO 2 (15 % CO 2 in N 2 ) into cyclic carbonate with an excellent yield at 80 °C and initial 3.0 MPa pressure.…”

Efficient Catalysts In situ Generated from Zinc, Amide and Benzyl Bromide for Epoxide/CO2 Coupling Reaction at Atmospheric Pressure

“…Ema and co‐workers synthesized bifunctional Mg II porphyrin catalysts bearing eight tetraalkylammonium bromide groups with alkyl chain, which presented high catalytic activity (turnover frequency, 19,000 h –1 ) . Bifunctional polymers by combining imidazolium‐based ionic liquids with zinc(II) porphyrin were designed by Ji group, and exhibited good catalytic performance and excellent recyclability …”