A porous Zn-based metal-organic framework with an expanded tricarboxylic acid ligand for effective CO2 capture and CO2/CH4 separation

摘要

A trigonal nanosized carboxylate ligand, 4, 4',4 ''-(triazine-2,4,6-triyl-tris(benzene-4,1-diy1))tribenzoic acid (H(3)TAPB), has been applied in the construction of a highly porous metal - organic framework (MOF). A solvothermal reaction of H(3)TAPB and a zinc salt in a mixed solvent of DEF/d ioxane/H2O produces the targeted porous MOF [Zn-3(TAPB)(2)(H2O)(2)](DEF)(4)(H2O)(3) (1, DEF = N,N-Dielhylformamide). This MOF contains a linear Zn-3 secondary building unit with two terminal water molecules occupied the axis positions, which is connected by the TAPB(3-) ligands to afford a 3-fold interpenetrated framework with a large calculated void volume (69.7%). The activated MOF shows exceptional porosities and high CO2 uptake capacities as well as good sorption selectivity of CO2/CH4 around room temperature.