Metal-Free Amine-Anchored Triazine-Based Covalent Organic Polymers for Selective CO₂ Adsorption and Conversion to Cyclic Carbonates Under Mild Conditions

Abstract

Attaining both large uptake and high conversion of CO2 under mild reaction conditions within a metal-free covalent organic polymer (COP) is an attractive and challenging strategy for CO2 utilization because CO2 is an abundant and renewable C1 source and a main greenhouse gas. In this study, novel amine-anchored covalent triazine aromatic polymers (CTP-1-NH2 and CTP-2-NH2) were synthesized from 2-amino-4,6-dichloro-1,3,5-triazine, biphenyl, and 1,3,5-triphenylbenzene via facile Friedel–Crafts arylation for CO2 adsorption and conversion reaction. At 273 K and 1 bar, CTP-1-NH2 and CTP-2-NH2 exhibited CO2 uptakes of 187.4 and 224.41 mg/g and CO2/N2 selectivity of 69.45 and 61.38, respectively, outperforming many previously reported COP materials. Moreover, metal-free CTP-1-NH2 with tetrabutylammonium bromide (n-Bu4NBr) exhibited high epoxide conversion and product selectivity under mild (40 °C and 1 bar) and solvent-free conditions within 36 h of reaction time, which were very much comparable to the performances of many metal-coordinated COP catalysts. The spent catalyst was also highly reusable with no active species leaching. A plausible mechanism for CO2 cycloaddition over the CTP-1-NH2 catalyst is proposed. Incorporating amine functionalities into a nitrogen-rich structure could be a promising strategy for developing materials with simultaneous CO2 capture and conversion.

Ionic Porous Organic Polymer Loaded with Zn(II) Ions for Efficient Cycloaddition of CO2 and Epoxides to Cyclic Carbonate

“…On the contrary, BO with electron-pushing substituents has the same high conversion as PO. In addition, the conversion of internal epoxides CHO and VCHO is relatively low due to the high resistance of their own structures. , We found that all epoxides maintained a selectivity of more than 96% for the formation of CCs, which proved that the Zn-HUT4/TBAB catalytic system was applicable in the selective formation of CCs. Moreover, in Table , we compared the catalytic performance of several M-POP catalysts in recent years.…”

Synthesis of Ultramicroporous Materials via Cross-Linking Reaction of Polynaphthalene

“…The N 2 adsorption capacity at 273.15 K/1.0 bar is 0.61 mmol/g, and CH 4 adsorption capacities at 273.15 K/1.0 bar and 298.15 K/1.0 bar are 1.57 and 1.14 mmol/g, respectively. The adsorption data of CH 4 at 273.15 K/1.0 bar are higher than those of some materials prepared in the past two years, such as SNNU-5-Sc (1.21 mmol g −1 ), CNOP-2 (1.37 mmol g −1 ), CTP-1-NH 2 (1.50 mmol g −1 ), and MOF-2 (0.63 mmol g −1 ) . Moreover, we also gained important data about the separations of CO 2 from N 2 and CH 4 .…”

Thermally Stable and High-Surface-Area Triptycene and Phenanthroline-Based Microporous Polymer for Selective CO2 Capture over CH4 and N2

“…Similar open-loop hysteresis behaviors have been previously reported for several hypercross-linked polymers with narrow-sized pores. 18,22,23 BETspecific surface area (SA BET ) of TPPM was measured to be 1120 m 2 g −1 (BET linear plot shown in Supporting Information, Figure S1). TPPM exhibited a total pore volume (V tot ) of 0.650 cm 3 g −1 and a micropore volume (V mic ) of 0.445 cm 3 g −1 (Table 1).…”