Building N‐Heterocyclic Carbene into Triazine‐Linked Polymer for Multiple CO₂ Utilization

Abstract

The development of new CO 2 detection technologies and CO 2 "capture-conversion" materials is of great significance due to the growing environmental crisis. Here, multifunctional triazinelinked polymers with built-in N-heterocyclic carbene (NHC) sites (designated as NHC-triazine@polymer) are presented for simultaneous CO 2 detection, capture, activation, and catalytic conversion. NHC-triazine@polymer were readily obtained through polymerization of cyanophenyl-substituted NHC. The obtained film-like polymers exhibited interesting CO 2-triggered fluorescence "turn-on" response and CO 2-sensitive reversible color change. Both NHC and triazine sites could act as efficient binding sites for CO 2 , and the CO 2 uptake of NHC and triazine reached 1.52 and 1.36 mmol g À 1 , respectively. Notably, after being captured by NHC, CO 2 was activated into a zwitterionic adduct NHCÀ CO 2 that could be easily transformed into cyclic carbonate in the presence of epoxides. Moreover, NHCtriazine@polymer were stable and active catalysts for the conversion of low-concentration CO 2 in a gas mixture (7 vol %) into cyclic carbonates as well as for hydrosilylation of CO 2 to formamides.

Strategic design of a bifunctional Ag(i)-grafted NHC-MOF for efficient chemical fixation of CO2 from a dilute gas under ambient conditions

“…64,65 In addition, the hysteresis behavior observed in CO 2 adsorption isotherms indeed supports the favorable interaction of CO 2 with the NHC sites. [66][67][68] Furthermore, a selective gas adsorption study (Fig. 2C) revealed negligible uptake of CH 4 and N 2 with the estimated Henry selectivity constants of 58 and 53 for CO 2 /CH 4 and CO 2 /N 2 , respectively (Fig.…”

Metal-Free Heptazine-Based Porous Polymeric Network as Highly Efficient Catalyst for CO2 Capture and Conversion

“…In this regard, several strategies have been employed for modulation of the pore surfaces to induce selective gas adsorption property in the framework by the incorporation of Lewis acidic/basic sites and immobilization of polar functional groups (-NO 2 , -NH 2 , -CONH 2 , -CF 3 , etc.) (Yue et al, 2020). On the other hand, CO 2 has gained considerable interest as a renewable, non-toxic, inexpensive, and an abundant C1 building block for high-value chemicals and fuels (Sakakura et al, 2007;Chu, 2009;Jacobson, 2009).…”

Bifunctional Catalysts with Core–Shell Distributed ZrO2 and Co Nanoparticles Derived from MOF-on-MOF Heterostructures for Economical One-Pot Tandem CO2 Fixation

“…The hydrogenation of nitroarenes to corresponding amines catalyzed by transition metals and the N -formylation reaction of amines with CO 2 in the presence of silanes using Lewis bases as catalysts have been well researched previously. − However, the integration of the above two reactions into a one-pot tandem reaction is scarcely reported, which is obviously a much more economical strategy for CO 2 fixation due to its lowered energy/time consumption in operation, reduced intermediate loss, and improved product yields. Herein, relying on our designed bifunctional core–shell ZrO 2 /C@ x -Co-NC catalysts with active Co NPs and ZrO 2 NPs for hydrogenation and N -formylation, respectively, this tandem reaction is realized and optimized under mild reaction conditions.…”