Observation of binding of carbon dioxide to nitro-decorated metal–organic frameworks. Issue 20 (14th May 2020)

• Record Type: Journal Article
• Authors: Duong, Thien D.; Sapchenko, Sergey A.; da Silva, Ivan; Godfrey, Harry G. W.; Cheng, Yongqiang; Daemen, Luke L.; Manuel, Pascal; Frogley, Mark D.; Cinque, Gianfelice; Ramirez-Cuesta, Anibal J.; Yang, Sihai; Schröder, Martin
• Is Part Of: Chemical science. Volume 11:Issue 20(2020)
• Page Start: 5339
• Page End: 5346
• Publication Date: 2020-05-14
• Subjects: Chemistry -- Periodicals; 540.5
• DOI: 10.1039/c9sc04294f
• Languages: English
• ISSNs: 2041-6520

Abstract

Abstract : Synergistic effects between –NO2 groups and open metal sites lead to optimal binding of CO2 molecules within MFM-102-NO2 via hydrogen bonding to C–H groups. Abstract : Metal–organic frameworks (MOFs) functionalised with amine, amide and hydroxyl groups show great promise for CO2 binding due to their ability to form hydrogen bonds to CO2 . Herein we report the adsorption and selectivity of CO2 in four iso-reticular MOFs adopting the NbO topology. Functionalisation of the parent MOF, MFM-102, with –NO2, –NH2 and alkyl groups leads to an enhancement of CO2 adsorption of up to 36% for the NO2 -decorated MOF and with raised selectivity. MFM-102-NO2 shows the highest adsorption capacity for CO2 (184 cm 3 g −1 at 273 K and 1.0 bar) within this series, comparable to the best-behaving iso-reticular MOFs. At 298 K and 1.0 bar, MFM-102-NO2 shows a CO2 /CH4 selectivity of 5.0. In situ inelastic neutron scattering and synchrotron FT-IR micro-spectroscopy were employed to elucidate the host–guest interaction dynamics within CO2 -loaded MFM-102-NO2 . Neutron powder diffraction enabled the direct observation of the preferred binding domains in MFM-102-NO2, and, to the best of our knowledge, we report the first example of CO2 binding to a –NO2 group in a porous MOF. Synergistic effects between the –NO2 group and the open metal sites lead to optimal binding of CO2 molecules within MFM-102-NO2 via hydrogen bonding to C–H groups.