3D porous polymers for selective removal of CO2 and H2 storage: experimental and computational studies

• Published in: Frontiers in chemistry 2023-09, Vol.11, p.1265324-1265324
• Main Authors: Al-Bukhari, Muath S., Abdulazeez, Ismail, Abdelnaby, Mahmoud M., Aljundi, Isam H., Al Hamouz, Othman Charles S.
• Format: Article
• Language: English
• Subjects: 3D porous polymers; Chemistry; CO2 capture; flue gas purification; global warming; H2 storage
• ISSN: 2296-2646; 2296-2646
• DOI: 10.3389/fchem.2023.1265324

In this article, newly designed 3D porous polymers with tuned porosity were synthesized by the polycondensation of tetrakis (4-aminophenyl) methane with pyrrole to form M1 polymer and with phenazine to form M2 polymer. The polymerization reaction used p -formaldehyde as a linker and nitric acid as a catalyst. The newly designed 3D porous polymers showed permanent porosity with a BET surface area of 575 m 2 /g for M1 and 389 m 2 /g for M2 . The structure and thermal stability were investigated by solid 13 C-NMR spectroscopy, Fourier-transform infrared (FT-IR) spectroscopy, and thermogravimetric analysis (TGA). The performance of the synthesized polymers toward CO 2 and H 2 was evaluated, demonstrating adsorption capacities of 1.85 mmol/g and 2.10 mmol/g for CO 2 by M1 and M2 , respectively. The importance of the synthesized polymers lies in their selectivity for CO 2 capture, with CO 2 /N 2 selectivity of 43 and 51 for M1 and M2 , respectively. M1 and M2 polymers showed their capability for hydrogen storage with a capacity of 66 cm 3 /g (0.6 wt%) and 87 cm 3 /g (0.8 wt%), respectively, at 1 bar and 77 K. Molecular dynamics (MD) simulations using the grand canonical Monte Carlo (GCMC) method revealed the presence of considerable microporosity on M2 , making it highly selective to CO 2 . The exceptional removal capabilities, combined with the high thermal stability and microporosity, enable M2 to be a potential material for flue gas purification and hydrogen storage.