A Dy6-cluster-based fcu-MOF with efficient separation of C2H2/C2H4 and selective adsorption of benzene

Abstract

The separation of C₂ hydrocarbon mixtures and VOCs is a very important and challenging process for industrial applications. Metal–organic frameworks (MOFs) have attracted extensive attention as an efficient separation material. In this study, a Dy-MOF {[(CH₃)₂NH₂]₂[Dy₆(μ₃-OH)₈(FTZB)₆(H₂O)₆]·(solvent)}_n based on the construction of Dy₆(μ₃-OH)₈(CO₂)₆(N₄C)₆ SBUs and F-H₂tzba (2-fluoro-4-(1H-tetrazol-5-yl)benzoic acid) has been synthesized, which with a high-symmetry fcu topology contains two types of cages modified by free –F groups and uncoordinated tetrazolyl N atoms. The Dy-MOF exhibits high C₂H₂ and C₂H₄ storage and remarkable separation efficiency for C₂H₂–CH₄, C₂H₄–CH₄ and C₂H₂–C₂H₄ mixtures, as confirmed by breakthrough experiments. The MOF also shows significant selective adsorption ability for benzene/toluene and benzene/cyclohexane. The interactions between the MOF and the adsorbates were studied by molecular simulations.