Structural Regulation and Light Hydrocarbon Adsorption/Separation of Three Zirconium-Organic Frameworks Based on Different V-Shaped Ligands.

On the basis of different V-shaped ligands, three zirconium-organic frameworks (JLU-Liu45, Zr-SDBA, and Zr-OBBA) have been successfully constructed. By regulating spatial configuration and functional groups of organic ligands, these as-synthesized Zr-MOFs (MOF = metal-organic framework) display distinct structures and different light hydrocarbon adsorption/separation capabilities. JLU-Liu45, with a double-walled interpenetrated 3D primitive cubic (pcu) framework, exhibits good gas-adsorption capacity but not prominent selective separation ability. Through regulating sizes and torsion angles of the organic ligands, Zr-SDBA possesses a 2D square lattice (sql) network, while Zr-OBBA displays a non-interpenetrated 3D pcu framework. Furthermore, by regulating functional groups on the ligands, Zr-SDBA shows prominent C2H2 uptake (101.2 cm3·g-1) and the best C2H2/CH4 selectivity (230.5, 1:1) among the three Zr-MOFs, and Zr-OBBA shows a significant C3H8/CH4 selectivity (105.6, 1:1). This work demonstrates the feasibility of structural regulation for MOF materials in the light hydrocarbon adsorption/separation field.