Construction of N-Rich Aminal-Linked Porous Organic Polymers for Outstanding Precombustion CO₂ Capture and H₂ Purification: A Combined Experimental and Theoretical Study

Abstract

A large number of scientific investigations are needed for developing a sustainable solid sorbent material for precombustion CO2 capture in the integrated gasification combined cycle (IGCC) that is accountable for the industrial coproduction of hydrogen and electricity. Keeping in mind the industrially relevant conditions (high pressure, high temperature, and humidity) as well as good CO2/H2 selectivity, we explored a series of sorbent materials. An all-rounder player in this game is the porous organic polymers (POPs) that are thermally and chemically stable, easily scalable, and precisely tunable. In the present investigation, we successfully synthesized two nitrogen-rich POPs by extended Schiff-base condensation reactions. Among these two porous polymers, TBAL-POP-2 exhibits high CO2 uptake capacity at 30 bar pressure (57.2, 18.7, and 15.9 mmol g–1 at 273, 298, and 313 K temperatures, respectively). CO2/H2 selectivities of TBAL-POP-1 and 2 at 25 °C are 434.35 and 477.93, respectively. On the other hand, at 313 K the CO2/H2 selectivities of TBAL-POP-1 and 2 are 296.92 and 421.58, respectively. Another important feature to win the race in the search of good sorbents is CO2 capture capacity at room temperature, which is very high for TBAL-POP-2 (15.61 mmol g–1 at 298 K for 30 to 1 bar pressure swing). High BET surface area and good mesopore volume along with a large nitrogen content in the framework make TBAL-POP-2 an excellent sorbent material for precombustion CO2 capture and H2 purification.

CO2–Philic Fluorinated Porous Organic Polyaminal in Photocatalytic Thiol–Ene Chemistry: Decoding the Effect of F-Atoms

“…Disappearance of the −NH 2 deformation band of BDTAB around 1658 cm –1 in all polymers confirms the condensation reaction between the amine-containing monomer and three aldehydes to form −CN– or −C–NH–. A sharp IR band at 1540 cm –1 (characteristic band for triazine ring) in the BDTAB monomer and in all three aminal-linked polymers indicates the completion of polycondensation reaction. , The absence of the imine (−CN) stretching band at 1620 cm –1 and the presence of a broad band around 3415 cm –1 suggest the formation of three polymeric networks through −C–NH– bonding that confirms the formation of aminal linkage (−C–NH−) in all polymers. The solid-state 13 C cross-polarization (CP) magic angle spinning (MAS) NMR spectra also confirm the construction of three polymeric networks, as represented in Figure b.…”

Selective Carbon Dioxide Capture and Ultrahigh Iodine Uptake by Tetraphenylethylene-Functionalized Nitrogen-Rich Porous Organic Polymers

“…The activated POPs start to adsorb CO 2 gradually in the low-pressure region. TTPEPOP-O and TTPEPOP-S exhibit acceptable CO 2 uptakes at 1 bar (2.34 and 2.94 mmol g –1 at 273 K, respectively, and 1.48 and 1.81 mmol g –1 at 298 K, respectively, Table ), which are comparable to those observed in aminal-linked porous polymers such as TBAL-POP-1 NRPPs, APOPs, and MBPP. − To gain insight on the interaction of the polymers with the adsorbate, the isosteric heat of CO 2 adsorptions ( Q st ) of TTPEPOP-O and TTPEPOP-S was calculated by fitting the CO 2 isotherms at 273 and 298 K and using the virial equation (see the SI document). As revealed in Figure S4, the Q st values for CO 2 reached 26.2 kJ mol –1 for TTPEPOP-O and 24.3 kJ mol –1 for TTPEPOP-S at zero surface coverage (Table ), indicating respectable binding affinity of CO 2 with the pore walls of the polymers presumably due to the presence of heteroatom-rich moieties.…”