08/06/2026
#𝐌𝐚𝐭𝐞𝐫𝐢𝐚𝐥𝐬𝐌𝐨𝐧𝐝𝐚𝐲 | 𝐏𝐨𝐫𝐨𝐮𝐬 𝐎𝐫𝐠𝐚𝐧𝐢𝐜 𝐏𝐨𝐥𝐲𝐦𝐞𝐫𝐬: 𝐓𝐡𝐞 𝐑𝐢𝐬𝐞 𝐨𝐟 𝐒𝐨𝐥𝐢𝐝 𝐀𝐛𝐬𝐨𝐫𝐛𝐞𝐧𝐭 𝐌𝐚𝐭𝐞𝐫𝐢𝐚𝐥𝐬 𝐢𝐧 𝐃𝐢𝐫𝐞𝐜𝐭 𝐀𝐢𝐫 𝐂𝐚𝐩𝐭𝐮𝐫𝐞
Direct Air Capture (DAC) is an innovative technology that directly extracts CO2 from the ambient air. Unlike traditional carbon capture methods that target concentrated CO2 streams from industrial sources (5-25 vol%), DAC addresses the challenge of capturing CO2 from low-concentration atmospheric regions (~420 ppm) (Arora, S. et al., 2026). The separated CO2 can then be stored permanently deep underground or be repurposed and converted into products (DOE, 2026).
In a comprehensive review, one of the listed DAC technologies available includes solid absorbent materials, particularly Porous Organic Polymers. These materials work through adsorption mechanisms, specifically chemisorption. They are considered highly attractive materials due to their covalent frameworks, which offer superior chemical stability and structural tunability under harsh conditions (Kazemi, S. et al., 2025). They also have configurable microporosity, excellent thermal stability, and very high surface areas reaching up to 5640 m²/g, which provide them with large internal volumes for CO2 interactions (Lakshmanan, A. et al., 2026).
They capture CO2 through direct air contact, then use heat to release the captured CO2 and restore the material’s ability to capture CO2 again. This thermal regeneration is necessary because the high nitrogen content in POPs leads to strong chemical interactions with CO2. While this bonding provides excellent capture capacity, once the loading capacity is reached, the captured CO2 saturates the sorbents. To maintain the material’s adsorption efficacy, thermal energy is used to break these bonds, releasing the captured gas, which is then ready to recapture more CO2 (Chen, Y. et al., 2025). It’s akin to emptying a container before refilling.
Due to its use as a filtration membrane, efforts to enhance its selectivity and, consequently, overall efficiency have been made. One study has made such modifications to this POP framework to improve performance. The researchers in the study have accomplished this by adding amide groups to the POP structure. This has been shown to strengthen multiple facets of the POP’s functionality. For one, gas adsorption was enhanced: the amide groups form stronger dipole-quadrupole and hydrogen-bond interactions with gas molecules. Secondly, improved chemical robustness. The POP membrane retained its functionality even after multiple recovery cycles. The amide linkages were observed to retain structural integrity during the harsh regeneration process. Lastly, there is the overall performance enhancement: In comparison to non-functional frameworks, which only have weak van der Waals interactions with low gas adsorption energy (10-40 kJ mol-1), the amide-functionalized Am-POP achieves Qst values of 39 kJ mol-1 for C2H2 and 31 kJ mol-1 for CO2 (Lakshmanan, A. et al., 2026).5
Given advancements in material modification and selection, one of the main challenges or limitations of DAC is its current cost when building the DAC system. Removing CO2 from ambient air, where there’s a low concentration of CO2, is highly energy-intensive. Additionally, storing or repurposing the captured CO2 incurs additional costs (DOE, 2026). On top of that, the sheer physical scale of air contactors in a DAC system is highly inefficient. To capture millions of metric tons of CO2 annually, a DAC system would need structures several meters high and several kilometers long, which would require large quantities of construction materials and chemicals. Thus, DAC is currently not an economically viable approach to mitigating climate change. Nonetheless, DAC is still one of the few strategies that might offer hope of lowering atmospheric CO2 concentrations someday. The wide-open science and engineering issues that will determine ultimate feasibility and competitiveness involve alternative strategies for moving the air and alternative chemical routes to sorption and regeneration (American Physical Society, 2011).
𝐑𝐄𝐅𝐄𝐑𝐄𝐍𝐂𝐄𝐒
Arora, S., Kannapu, H. P. R., Kamboj, V., McGinley, M., & Sunkara, M. K. (2026). Direct Air Capture of Carbon Dioxide: A Comprehensive Review. Sustainable Chemistry One World, 100249. https://doi.org/10.1016/j.scowo.2026.100249
DOE (2026). DOE Explains. . .Direct air capture.
Chen, Y., Wu, R., & Hsu, P. (2025). Perspective on distributed direct air capture: what, why, and how? Npj Materials Sustainability, 3(1).
American Physical Society (2011). Direct Air Capture of CO2 with Chemicals. https://www.aps.org/publications/reports/direct-air-capture-co2
Kazemi, S., Tadjarodi, A., & Moghaddam, A. B. (2025). Multilayer chemisorption-enabled MOF-based composite membrane for rapid and efficient trifluralin removal from wastewater. Scientific Reports, 15(1), 10519. https://doi.org/10.1038/s41598-025-94438-8
Lakshmanan, A., Bilal, H. M., Erum, J. K. E., Xia, X., Zhao, T., Alshahrani, T., & Gao, J. (2026). Matrix-Sacrificial Chemically Recoverable Amide-Linked Porous Organic Polymer Sorbent-Based Membrane for Synergistic Gas Capture and Particulate Matter Filtration. Results in Engineering, 111415. https://doi.org/10.1016/j.rineng.2026.111415
𝑴𝒂𝒕𝒆𝒓𝒊𝒂𝒍𝒔 𝑴𝒐𝒏𝒅𝒂𝒚 𝒊𝒔 𝒃𝒓𝒐𝒖𝒈𝒉𝒕 𝒕𝒐 𝒚𝒐𝒖 𝒃𝒚 𝑴𝑨𝑻𝑬𝑺-𝑴𝑼. 𝐌𝐚𝐭𝐞𝐫𝐢𝐚𝐥𝐬 𝐌𝐨𝐧𝐝𝐚𝐲 (𝐌𝐌) 𝒊𝒔 𝒐𝒖𝒓 𝒘𝒆𝒆𝒌𝒍𝒚 𝒃𝒊𝒕𝒆-𝒔𝒊𝒛𝒆𝒅 𝒄𝒐𝒏𝒕𝒆𝒏𝒕 𝒔𝒆𝒓𝒊𝒆𝒔 𝒇𝒆𝒂𝒕𝒖𝒓𝒊𝒏𝒈 𝒓𝒆𝒂𝒍-𝒘𝒐𝒓𝒍𝒅 𝒂𝒑𝒑𝒍𝒊𝒄𝒂𝒕𝒊𝒐𝒏𝒔 𝒐𝒇 𝑴𝒂𝒕𝒆𝒓𝒊𝒂𝒍𝒔 𝑺𝒄𝒊𝒆𝒏𝒄𝒆 𝑬𝒏𝒈𝒊𝒏𝒆𝒆𝒓𝒊𝒏𝒈—𝒇𝒓𝒐𝒎 𝒆𝒗𝒆𝒓𝒚𝒅𝒂𝒚 𝒑𝒓𝒐𝒅𝒖𝒄𝒕𝒔 𝒂𝒏𝒅 𝒄𝒐𝒎𝒎𝒆𝒓𝒄𝒊𝒂𝒍 𝒕𝒆𝒄𝒉 𝒕𝒐 𝒐𝒄𝒄𝒂𝒔𝒊𝒐𝒏𝒂𝒍 𝒑𝒐𝒑 𝒄𝒖𝒍𝒕𝒖𝒓𝒆 𝒓𝒆𝒇𝒆𝒓𝒆𝒏𝒄𝒆𝒔. 𝑻𝒉𝒊𝒔 𝒄𝒐𝒏𝒕𝒆𝒏𝒕 𝒊𝒔 𝒊𝒏𝒕𝒆𝒏𝒅𝒆𝒅 𝒔𝒕𝒓𝒊𝒄𝒕𝒍𝒚 𝒇𝒐𝒓 𝒂𝒄𝒂𝒅𝒆𝒎𝒊𝒄 𝒂𝒏𝒅 𝒆𝒅𝒖𝒄𝒂𝒕𝒊𝒐𝒏𝒂𝒍 𝒑𝒖𝒓𝒑𝒐𝒔𝒆𝒔.
Content: Joshua Lorenz Gaa
Design: Liv Laroco
