Abstract
Metal-organic frameworks (MOFs) functionalised with amine, amide and hydroxyl groups show great promise for CO2binding due to their ability to form hydrogen bonds to CO2. Herein we report the adsorption and selectivity of CO2in four iso-reticular MOFs adopting the NbO topology. Functionalisation of the parent MOF, MFM-102, with -NO2, -NH2and alkyl groups leads to an enhancement of CO2adsorption of up to 36% for the NO2-decorated MOF and with raised selectivity. MFM-102-NO2shows the highest adsorption capacity for CO2(184 cm3g-1at 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-NO2shows a CO2/CH4selectivity of 5.0.In situinelastic 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 CO2binding to a -NO2group in a porous MOF. Synergistic effects between the -NO2group and the open metal sites lead to optimal binding of CO2molecules within MFM-102-NO2viahydrogen bonding to C-H groups.
Original language | English |
---|---|
Pages (from-to) | 5339-5346 |
Number of pages | 8 |
Journal | Chemical Science |
Volume | 11 |
Issue number | 20 |
DOIs | |
State | Published - May 28 2020 |
Funding
We thank EPSRC (EP/I011870), the Royal Society and University of Manchester for funding. This project has received funding from the European Research Council (ERC) under the European Union's Horizon 2020 research and innovation programme (grant agreement no 742401, NANOCHEM). We thank ISIS/ STFC, Diamond Light Source and Oak Ridge National Laboratory for access to Beamlines WISH, B22 and VISION, respectively. Neutron scattering experiments were performed at ORNL's Spallation Neutron Source, supported by the Scientic User Facilities Division, Office of Basic Energy Sciences, US DOE, under Contract No. DE-AC0500OR22725 with UT Battelle, LLC. The computing resources were made available through the VirtuES and the ICE-MAN projects, funded by Laboratory Directed Research and Development program and Compute and Data Environment for Science (CADES) at ORNL. We thank EPSRC (EP/I011870), the Royal Society and University of Manchester for funding. This project has received funding from the European Research Council (ERC) under the European Union's Horizon 2020 research and innovation programme (grant agreement no 742401, NANOCHEM). We thank ISIS/STFC, Diamond Light Source and Oak Ridge National Laboratory for access to Beamlines WISH, B22 and VISION, respectively. Neutron scattering experiments were performed at ORNL's Spallation Neutron Source, supported by the Scientific User Facilities Division, Office of Basic Energy Sciences, US DOE, under Contract No. DE-AC0500OR22725 with UT Battelle, LLC. The computing resources were made available through the VirtuES and the ICE-MAN projects, funded by Laboratory Directed Research and Development program and Compute and Data Environment for Science (CADES) at ORNL.