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

The separation of ethane (C 2 H 6 ) and ethylene (C 2 H 4 ) 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 C 2 H 6 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 C 2 H 6 /C 2 H 4 separation. Density functional theory (DFT) simulations reveal that this preferential ethane adsorption originates from enhanced van der Waals interactions between C 2 H 6 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 C 2 H 6 /C 2 H 4 separation processes, offering possibilities for advanced hydrocarbon purification technologies.