Unveiling molecular level detail of CO2 adsorption in several extensive families of metal-organic frameworks

High atm. CO2 levels, resulting largely from combustion of fossil fuels, and its undesirable impact on global climate has sparked considerable interest in cleaner energy sources. While energy transitions are historically slow, technol. solns. for mitigation of current CO2 emissions is becoming more evident. It is projected that use of phys. adsorbents with low-energy regeneration requirements, like metal-org. frameworks, could reduce parasitic loss assocd. with current capture technologies. Metal org. frameworks (MOFs) are cryst. materials that contain metal-ions or metal-ion clusters as nodes and org. ligands as linkers to form 1-, 2-, and 3-D structures. These materials are being intensely investigated because they readily undergo chem. modification for tuning framework properties, exhibit record-breaking internal surface areas, and have demonstrated selectivity and reversibility in the adsorption of small guest mols. Gas adsorption measurements have been carried out in tandem with in-situ diffraction studies, unveiling mol. level detail of CO2 adsorption within several extensive families of MOFs. Results are compared with DFT calcns. used to predict the CO2 adsorbed structures as well as the isosteric heats of CO2 adsorption. The exptl. results show good agreement with theory in all cases.