A robust triphenylamine-based monolithic polymer network for selective sieving of CO2 and PM from flue gas

• Published in: The Science of the total environment 2024-10, Vol.946, p.174463, Article 174463
• Main Authors: Lei, Yang, Wang, Shaozhen, Jiang, Yanli, Li, Zhen, Liu, Nana, Xu, Yuan, Yu, Jiao, Cui, Mengjiao, Li, Yang, Zhao, Li
• Format: Article
• Language: English
• Subjects: Acid and base tolerance; Column breakthrough experiments; Ideal adsorbed solution theory; Low penetration resistance; Triphenylamine active site
• ISSN: 0048-9697; 1879-1026; 1879-1026
• DOI: 10.1016/j.scitotenv.2024.174463

The increasingly urgent issue of climate change is driving the development of carbon dioxide (CO2) capture and separation technologies in flue gas after combustion. The monolithic adsorbent stands out in practical adsorption applications for its simplified powder compaction process while maintaining the inherent balance between energy consumption for regeneration and selectivity for adsorption. However, optimizing the adsorption capacity and selectivity of CO2 separation materials remains a significant challenge. Herein, we synthesized monolithic polymer networks (N-CMPs) with triphenylamine adsorption sites, acid-base environment tolerance, and precise narrow microchannel pore systems for the selective sieving of CO2 and particulate matter (PM) in flue gas. The inherent continuous covalent bonding of N-CMPs, along with their highly delocalized π-π conjugated porous framework, ensures the stability of the monolithic polymer network's adsorption and separation capabilities under wet and acid-base conditions. Specifically, under the conditions of 1 bar at 273 K, the CO2 adsorption capacity of N-CMP-1 is 3.35 mmol/g. Attributed to the highly polar environment generated by triphenylamine and the inherent high micropore/mesopore ratio, N-CMPs exhibit an excellent ideal adsorbed solution theory (IAST) selectivity for CO2/N2 under simulated flue gas conditions (CO2/N2 = 15:85). Dynamic breakthrough experiments further visualize the high separation efficiency of N-CMPs in practical adsorption applications. Moreover, under acid-base conditions, N-CMPs achieve a capture efficiency exceeding 99.76 % for PM0.3, enabling the selective separation of CO2 and PM in flue gas. In fact, the combined capture of hazardous PM and CO2 from the exhaust gases produced by the combustion of fossil fuels will play a pivotal role in mitigating climate change and environmental issues until low-carbon and alternative energy technologies are widely adopted. A trianiline-coupled microporous polymer (N-CMPs) is a novel multifunctional material capable of simultaneously capturing PM and CO2 in flue gas. Through the introduction of nitrogen atoms, the hollow nanotube morphology and hierarchical porous structure not only enables efficient removal of PM from the air under high temperature and acidic or basic conditions but also exhibits remarkable selectivity for CO2/N2 adsorption separation. Further validation of the high-efficiency CO2/N2 separation potential of N-CMPs in practical environme