Adsorptive capturing and storing greenhouse gases such as sulfur hexafluoride and carbon tetrafluoride using metal-organic frameworks

High pressure excess adsorption isotherms of sulfur hexafluoride (SF6) and tetrafluoromethane (CF4) on metal-organic frameworks Cu3(btc)2 (HKUST-1, btc - benzene-1,3,5-tricarboxylate), Fe3FO(H2O)2(btc)3 (MIL-100), Cr3F(H2O)2O(1,4-bdc)3 (MIL-101, 1,4-bdc - 1,4-benzenedicarboxylate), Co2(1,4-bdc)2(dabco) (dabco-1,4-diazabicyclo[2.2.2]octane), Ni2(2,6-ndc)2(dabco) (DUT-8, 2,6-ndc - 2,6-naphthalenedicarboxylate), Ni2O5(btb)2 (DUT-9, btb - benzene-1,3,5-tribenzoate), Zn4O(btb), and (Zn4O(dmcpz)3) (dmcpz - 3,5-dimethyl-4-carboxypyrazolato) at 298 K were investigated using volumetric methods. Up to 1 bar pressure (at 298 K), microporous MOF with open metal sites HKUST-1 shows the best performance in SF6 adsorption and microporous Zn4O(dmcpz)3 in CF4 adsorption. At high pressure, mesoporous MIL-101 and DUT-9 have the highest storage capacities for both gases among the MOFs investigated.