A NbO-type MOF based on an aromatic-rich and N-functionalized diisophthalate ligand for high-performance acetylene storage and purification

Abstract

A porous MOF ZJNU-93 based on a custom-designed diisophthalate ligand bearing an aromatic-rich backbone and N-functionalized sites was solvothermally synthesized and fully characterized. Single-crystal X-ray diffraction studies revealed that ZJNU-93 is a three-dimensional (4,4)-connected NbO-type network composed of dicopper paddlewheel units and organic linkers as 4-connected building blocks. Furthermore, its gas adsorption properties with respect to C₂H₂, CO₂, and CH₄ were systematically studied, revealing its promising utility as an adsorbent for the storage as well as separation and purification of C₂H₂. More specifically, the C₂H₂ uptake capacity reaches 164.0 cm³ (STP) g⁻¹, while the estimated C₂H₂/CO₂ and C₂H₂/CH₄ adsorption selectivities are as high as 4.5 and 34.4 at 298 K and 1 atm. ZJNU-93 represents a rare MOF displaying high C₂H₂ storage and separation capacities at the same time.