Suitability of a diamine functionalized metal-organic framework for direct air capture

• Published in: Chemical science (Cambridge) 2023-09, Vol.14 (35), p.938-9388
• Main Authors: Bose, Saptasree, Sengupta, Debabrata, Malliakas, Christos D, Idrees, Karam B, Xie, Haomiao, Wang, Xiaoliang, Barsoum, Michael L, Barker, Nathaniel M, Dravid, Vinayak P, Islamoglu, Timur, Farha, Omar K
• Format: Article
• Language: English
• Subjects: Adsorption; Carbon dioxide; Carbon dioxide concentration; Carbon sequestration; Chemistry; Diamines; Gas chromatography; Infrared analysis; Infrared spectroscopy; INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY; Metal-organic frameworks; Porous materials; Regeneration; Relative humidity; Stability; Thermogravimetric analysis; Titration
• ISSN: 2041-6520; 2041-6539
• DOI: 10.1039/d3sc02554c

The increase in the atmospheric carbon dioxide level is a significant threat to our planet, and therefore the selective removal of CO 2 from the air is a global concern. Metal-organic frameworks (MOFs) are a class of porous materials that have shown exciting potential as adsorbents for CO 2 capture due to their high surface area and tunable properties. Among several implemented technologies, direct air capture (DAC) using MOFs is a promising strategy for achieving climate targets as it has the potential to actively reduce the atmospheric CO 2 concentration to a safer levels. In this study, we investigate the stability and regeneration conditions of N , N ′-dimethylethylenediamine (mmen) appended Mg 2 (dobpdc), a MOF with exceptional CO 2 adsorption capacity from atmospheric air. We employed a series of systematic experiments including thermogravimetric analysis (TGA) coupled with Fourier transformed infrared (FTIR) and gas chromatography mass spectrometer (GCMS) (known as TGA-FTIR-GCMS), regeneration cycles at different conditions, control and accelerated aging experiments. We also quantified CO 2 and H 2 O adsorption under humid CO 2 using a combination of data from TGA-GCMS and coulometric Karl-Fischer titration techniques. The quantification of CO 2 and H 2 O adsorption under humid conditions provides vital information for the design of real-world DAC systems. Our results demonstrate the stability and regeneration conditions of mmen appended Mg 2 (dobpdc). It is stable up to 50% relative humidity when the adsorption temperature varies from 25-40 °C and the best regeneration condition can be achieved at 120 °C under dynamic vacuum and at 150 °C under N 2 . A comprehensive examination of mmen-Mg 2 (dobpdc) as a direct air capture adsorbent to determine its practical feasibility and performance for potential industrialization in mitigating climate change by reducing atmospheric CO 2 levels.