Role of aromatic ring spacer in homo‐coupled conjugated microporous polymers in selective CO₂ separation

Abstract

To obtain high purity of natural and flue gases, the development of adsorbent with appropriate structure is of great importance. As a result, there is an urgent need to investigate the role of aromatic ring spacer in adsorbent in high CO 2 capture. For this, conjugated microporous polymers (CMPs) were fabricated through homo-coupling reaction of 1,3,5-tribromobenzene (TBB) and 1,3,5-triethynylbenzene (TEB). It was observed that, CMP-A (without spacer) demonstrates high CO 2 uptake over CMP-B (with spacer). CMP-A demonstrates CO 2 uptake of 212.1 mg g À1 which is obviously higher than benchmark adsorbents under the analogous conditions. In addition, the obtained CO 2 uptake is also higher than metal-organic framework (MOF) and energyintensive carbon-based adsorbents. CMP-A revealed high CO 2 /N 2 selectivity (78.5) over CMP-B (56.1). It was noticed that CMP-A demonstrates excellent CO 2 /CH 4 and CO 2 /N 2 selectivity over CMP-B at 273 K. This is mainly due to appropriate structure in CMP-A (without spacer). The obtained CO 2 /N 2 selectivity (78.5) is higher than recently reported adsorbents under the similar experimental conditions.

Rich oxygen atom-decorated conjugated microporous polymers for carbon dioxide capture

“…[11][12][13][14][15][16][17][18][19][20][21][22][23][24][25] We are drawn to conjugated microporous polymers (CMPs) due to their diverse synthetic methods, customizable pconjugation, and permanent micropore structure, which render them more suitable for carbon dioxide capture. [26][27][28][29][30][31][32][33][34][35][36][37][38] Recently, a range of chemical reactions have been employed for CMP synthesis. Transition metal-catalyzed coupling chemistries, including Suzuki and Sonogashira cross-coupling (Pd), [22][23][24] Yamamoto reaction (Ni), 25,26 and oxidative polymerization (Fe), 27 have been explored.…”

“…3c, red), which surpasses the values of O-CMP-1 and O-CMP-2 by 1.4 and 1.3 times, respectively. Notably, this value is comparable with those of reported POPs, including CMP-YA (2.10 mmol g À1 ), 21 Azo-Cz-CMP (2.14 mmol g À1 ), 32 PCZN-1 (2.56 mmol g À1 ), 35 Azo-Trip (2.71 mmol g À1 ), 34 N-MPOP (2.78 mmol g À1 ), 22 CMP-A (3.38 mmol g À1 ), 28 CMP-LS2 (3.90 mmol g À1 ), 33 CP-CMP5 (4.57 mmol g À1 ), 16 CMP-A (4.81 mmol g À1 ), 38 and PC-800 (5.4 mmol g À1 ). 37 This value is also comparable to those of reported POPs with hydroxyl groups, such as CMP-1-(OH) 2 (1.07 mmol g À1 ), 39 BFCMP-1 (2.45 mmol g À1 ), 40 and PAF-P5-OH (3.9 mmol g À1 ).…”