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.