Nanoporous Copper-Isoquinoline Coordination Polymer for High-Efficiency Ethane/Ethylene Separation

The separation of ethane (C₂H₆) and ethylene (C₂H₄) presents a critical industrial challenge due to their nearly identical molecular sizes and physical characteristics. In this study, we report a nanoporous copper-based metal-organic framework (Cu-iqc) constructed from rigid aromatic isoquinoline ligands, featuring nanometer precision in pore geometry (0.7 nm), which demonstrates an exceptional ethane-selective adsorption performance. The framework exhibits a remarkable C₂H₆ uptake capacity of 2.28 mmol/g at 298 K and 100 kPa, combined with an impressive ideal adsorbed solution theory (IAST) selectivity of 2.41 for C₂H₆/C₂H₄ separation. Density functional theory (DFT) simulations reveal that this preferential ethane adsorption originates from enhanced van der Waals interactions between C₂H₆ molecules and the precisely aligned aromatic rings within the framework’s optimally sized pores. These findings position Cu-iqc as a highly promising adsorbent for energy-efficient C₂H₆/C₂H₄ separation processes, offering possibilities for advanced hydrocarbon purification technologies.