CO2 capture from wet flue gas using a water-stable and cost-effective metal-organic framework

• Published in: Cell reports physical science 2023-07, Vol.4 (7), p.101470, Article 101470
• Main Authors: Loughran, Ryan P., Hurley, Tara, Gładysiak, Andrzej, Chidambaram, Arunraj, Khivantsev, Konstantin, Walter, Eric D., Graham, Trent R., Reardon, Patrick, Szanyi, Janos, Fast, Dylan B., Miller, Quin R.S., Park, Ah-Hyung Alissa, Stylianou, Kyriakos C.
• Format: Article
• Language: English
• Subjects: aluminum; carbon capture; cost-effective; flue gas; humid conditions; in situ characterization; INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY; metal-organic frameworks; molecular confinement; regeneration; ultramicroporous
• ISSN: 2666-3864; 2666-3864
• DOI: 10.1016/j.xcrp.2023.101470

We report the use of MIL-120 as a water-stable and cost-effective metal-organic framework (MOF) for selectively capturing CO2 from wet flue gas. Synthesized using inexpensive and environmentally benign reagents in water, MIL-120 possesses one-dimensional pores decorated with hydroxyl-bridged Al(III) ions and benzene rings with an interstitial spacing of 4.78 Å. Carbon dioxide isotherms show steep uptake at low pressure, and the affinity of MIL-120 for CO2 is 44 kJ mol−1. CO2-loading 13C solid-state nuclear magnetic resonance and Fourier transform infrared spectra tracking the sorption of CO2 into MIL-120 revealed that the interplay of pore size, functionality, and dimensionality is vital for CO2 restriction within the pores of MIL-120. Breakthrough experiments reveal that MIL-120 can capture CO2 from dry and wet flue gas with uptake capacities of 1.215 and 1.118 mmol g−1, respectively. Our work highlights the synthetic benefits of MIL-120 and elucidates its selective capture of CO2 from wet flue gas. [Display omitted] •Synthesis of a cost-effective and water-stable aluminum-based MOF•Pore size, shape, and functionality are key factors for the selective capture of CO2•In situ CO2-loading spectroscopy experiments provided insights into CO2 incarceration•MIL-120 can be regenerated and reused for wet flue gas CO2 capture Loughran et al. describe the use of MIL-120 as a cost-effective, ecologically sustainable, and water-stable MOF exhibiting selective CO2 uptake in humid flue gas conditions. Its regenerability as a CO2 adsorbent, as well as its conserved stability under high temperatures and water exposure, suggests its suitability for use in industry.