Rational construction and remarkable gas adsorption properties of a HKUST-1-like <i>tbo</i>-type MOF based on a tetraisophthalate linker

Abstract

To target a condensed version of the HKUST-1-like tbo-type MOF MFM-181, a new tetraisophthalate ligand, 3,6-dimethyl-1,2,4,5-tetra(5'-isophthalic acid)benzene, was rationally designed and synthesized based on ligand contraction and conformation preorganization strategy. Compared to its parent compound MFM-181, the resulting MOF ZJNU-10 features smaller cage sizes as well as higher density of open copper sites, thus endowing the material with the promising potential for C₂H₂/CH₄ and CO₂/CH₄ separations associated with C₂H₂ purification and natural gas sweetening. At 298 K and atmospheric pressure, the uptake capacities of C₂H₂ and CO₂ reach 151.5 and 108.3 cm³ (STP) g^-1, while the IAST-predicted adsorption selectivities of C₂H₂ and CO₂ over CH₄ are up to 29.9 and 7.6, respectively.