Robust Heterometallic TbIII/MnII–Organic Framework for CO2/CH4 Separation and I2 Adsorption

The exquisite combination of heterometallic [TbIIIMnII(CO2)3(H2O)2] clusters with the hexacarboxylate ligand of H6TDP generates one water-stable 3D heterometallic TbIII/MnII-organic framework material {TbMn­(HTDP)­(H2O)2]·5DMF·4H2O}n (NUC-3; H6TDP = 2,4,6-tri­(2′,4′-dicarboxyphenyl)­pyridine), which consists of functionalized noninterspersed opening nanochannels shaped by six rows of [TbIIIMnII(CO2)3(H2O)2] clusters. Based on the single-component sorption measurements, activated NUC-3 framework exhibits effective CO2/CH4 separation associated with high uptake and moderate adsorption enthalpy of CO2. Dynamic breakthrough experiments reveal that NUC-3 could be competent for the separation of CO2/CH4 (50:50, v:v) mixture. Moreover, the kinetic and equilibrium experiments of iodine adsorption indicate that NUC-3 possess excellent adsorption capacity for iodine molecules in cyclohexane solution. The excellent structural stability and functional internal surface makes NUC-3 a prospective adsorbent for practical CO2/CH4 separation and adsorption elimination of iodine molecules, opening up the insight of heterometallic MOFs for pratical application.