A facile synthesis of microporous organic polymers for efficient gas storage and separation

Abstract

A series of porous hyper-cross-linked polymers with excellent physiochemical stability have been designed and prepared facilely through template-free Friedel-Crafts alkylation reactions between benzene / biphenyl / 1,3,5-triphenylbenzene as co-condensing rigid aromatic building blocks and 1,3,5-tris(bromomethyl)benzene or 1,3,5-tris(bromomethyl)-2,4,6-trimehylbenzene as cross-linkers under the catalysis of anhydrous AlCl3 or FeCl3. The systematic study of gas uptake ability shows that anhydrous AlCl3 is a much more effective catalyst than anhydrous FeCl3. The synthesized polymers are thermally stable and are predominantly microporous with high surface areas up to 1783 m 2 g -1 . In addition, they exhibit high H2 and CO2 uptake capacity/selectivity. Among these materials, C1M3-Al has the highest H2 uptake capacity at 77 K and 1 bar (19.1 mg·g -1 ) and CO2 uptake capacity at 273 K and 1 bar (181 mg·g -1 ); the best CO2/N2 (15/85) selectivity calculated by IAST at 273 K and 1 bar belongs to C1M2-Al (32.3). Moreover, the synthesis route exhibits cost-effective advantages, which are essential for scale-up preparation, thus showing great potential for clean energy applications.

Hypercrosslinked organic polymer based carbonaceous catalytic materials: Sulfonic acid functionality and nano-confinement effect

“…Finally, the acid-functionalized product was obtained by filtration, washing with anhydrous DCM, extraction in a Soxhlet extractor with methanol for 24 h, and drying at 100 °C for 12 h. The C, H, S elemental analysis data for all the hypercrosslinked polymers were listed in Table S1. The deviations between theoretical and experimental values were observed on these polymers due to the incomplete alkylation and trapped adsorbates including catalyst, gases and water vapor within the pores, which are consistent with previous reports [33][34][35].…”

“…But in fact, the residual chlorine in the resulting polymer is found according to EDS ( Figure S1), indicating that there are chloromethyl groups that remain unsubstituted in the first step. Similar results are also reported by other groups with residual chlorine or bromine in the HCPs [33]. Figure 1A and C display the N 2 sorption results of all the two series of HCP materials, with the related textural properties being summarized in Table 1.…”

“…The two remarkable peaks at 132 and 141 ppm become adjacent in the spectra of HDS-4 and HBS-4, and change to be almost one peak in the spectrum of HDS-4. The above variation of NMR signals in the range of 130-145 ppm for the samples before and after sulfonation can be assigned to that the non-substituted aromatic carbon is affected by the adjacent one tethered with -SO 3 H group [33,41]. The resonance at around 55 ppm is the spinning side band [32].…”

Layered microporous polymers by solvent knitting method

“…Of these SHCP polymers, SHCP-3 with much higher microporosity exhibits the highest CO 2 uptake at 4.84 mmol g −1 (273 K and 1.00 bar). The CO 2 uptake of SHCP-3 is much higher than that of other HCP materials under similar conditions, such as TPB-based HCPs (3.61 mmol g −1 ) ( 39 ), binaphthol-based HCPs (3.96 mmol g −1 ) ( 40 ), and C1M1-Al (4.34 mmol g −1 ) ( 46 ), with the highest CO 2 uptake capacity for HCP materials reported thus far.…”

Covalent triazine polymers using a cyanuric chloride precursor via Friedel–Crafts reaction for CO2 adsorption/separation

“…Recently, POPs which can be constructed from light-weight elements linked by strong covalent bonds have attracted increasing attention for gas adsorption, storages and separation owing to their high stability against moisture, chemical stability with long lifetimes and easy handling [15]. These are known by their different product designations, such as Schiff base networks (SNWs) [16], benzimidazole-linked polymers (BILPs) [17], covalent triazine frameworks (CTFs) [18], polymers with intrinsic microporosity (PIMs) [19], porous aromatic frameworks (PAFs) [20], porous polymer frameworks (PPFs) [21], porous polymer networks (PPNs) [22], covalent organic frameworks (COFs) [23], element-organic frameworks (EOFs) [24], covalent organic polymers (COPs) [25], hypercrosslinked and conjugated microporous polymers (HCPs and CMPs) [26,27], covalent imine polymers (CIP) [28], and nitrogen-doped porous carbon materials (NPCs) [29]. The relatively low cost synthesis of this class of nitrogen chloride-catalyzed Friedel-Crafts reaction [33].…”