Construction of a Carbazole-Based Nanoporous Organic Polymer via an AB₂ Monomer for Adsorption/Separation of C₁–C₃ Alkanes and CO₂

Abstract

Herein, a carbazole-based nanoporous organic polymer (CNOP-5) was successfully constructed via the Friedel–Crafts (F–C) reaction of an AB2 carbazole monomer. The adsorption/separation performances of CO2 and C1–C3 light hydrocarbons are comparatively evaluated by testing their pure component gas adsorption isotherms. The CO2/CH4, C2H6/CH4, and C3H8/CH4 adsorption selectivities of CNOP-5 were calculated separately based on the ideal adsorbed solution theory (IAST). The results of IAST and dynamic breakthrough curves indicate that CNOP-5 can be an excellent adsorbent for the purification and recovery of C3H8, C2H6, and CH4 from natural gas.

Synthesis of a Carbazole-Based Nanoporous Organic Polymer for Efficient Adsorption/Separation of C2H2 and CO2

“…CNOP-6 exhibited higher Brunauer− Emmett−Teller (BET) surface areas than previously reported porous polymers, such as PNOPs (729−830 m 2 •g −1 ), 19 ANOPs (1052−1272 m 2 •g −1 ), 20 sPANs (65−113 m 2 •g −1 ), 21 TpPa-F (1048 m 2 •g −1 ), 11 and NUSs (582−720 m 2 •g −1 ). 19 CNOP-6 also demonstrated competitiveness with previously reported CNOPs, including CNOP-5 (1425 m 2 •g −1 ), 15 CNOPs (1374−1546 m 2 •g −1 ), 16 CNOPs (769−1007 m 2 • g −1 ), 17 and CPOP1-V3 (1210 m 2 •g −1 ). 22 The pore-size distribution of CNOP-6, as depicted in Figure 2b, was determined through nonlocal density functional theory.…”

“…Notably, the C 2 H 2 uptake obtained with CNOP-6 at 298 K exceeds those of previously reported NOPs, as displayed in Table S1, like TpPa-NO 2 (63.73 cm 3 ·g –1 ), TFT-COF (39.4 cm 3 ·g –1 ), and MeBP (64.6 cm 3 ·g –1 ) . Except for its higher C 2 H 2 uptake, CNOP-6 also exhibits an exceptional CO 2 uptake of 55.4 cm 3 ·g –1 under ambient conditions, which is competitive with the previously reported NOPs, like CNOPs (46.5–53.4 cm 3 ·g –1 ) − and NUSs (10.3–11.2 cm 3 ·g –1 ) . The high C 2 H 2 and CO 2 adsorption capacities in CNOP-6 are likely attributed to its rich carbazole units, higher BET surface area, and abundant microporous structure.…”

“…Carbazole-based nanoporous organic polymers (CNOPs) have gained significant attention because of their excellent thermal and chemical stability as well as their massive porosity. In recent years, numerous studies have concentrated on the synthesis of CNOPs using various synthetic reactions, including metal-catalyzed C–C cross-coupling reactions, FeCl 3 -catalyzed oxidative coupling reactions, , nitrile-based trimerization, and Friedel–Crafts (F–C) reactions. − Among these methods, the F–C reaction stands out as a straightforward approach for synthesizing NOPs. The F–C reaction offers several advantages, including the use of inexpensive catalysts, high polymerization yields, and compatibility with diverse building blocks.…”

“…Previous studies have shown that the incorporation of carbazole units into the polymer framework enhances the interaction between the gas molecules and the polymer framework. This enhancement improves the adsorption and separation performance of small gas molecules like CO 2 , C 2 H 6 , and C 3 H 8 . ,− However, to the best of our knowledge, there is a lack of literature assessing the adsorption and separation performance of high-value-added C 2 H 2 for CNOPs. This area remains understudied and presents an opportunity for further research to explore the potential of CNOPs in the adsorption and separation of C 2 H 2 .…”

Synthesis of triphenylamine-based nanoporous organic polymers for highly efficient capture of SO2 and CO2

“…To address this complexity and simplify nitrogen-containing NOP synthesis for SO 2 capture, we have previously proposed the use of AB 2 monomers. 28 Nevertheless, very few investigations have looked further in this direction.…”