Optimizing the pore space of a robust nickel-organic framework for efficient C2H2/C2H4 separation

The separation of acetylene (C2H2) from ethylene (C2H4) is an important but challenging process in industry because of their similar physical properties and kinetic molecular sizes. Here, we presented a robust nickel-organic framework (UPC-22) with intrinsic hydrogen bonds and one-dimensional functionalized channels, offering efficient purification of C2H4. UPC-22 exhibits excellent chemical stability at various pH values from 1 to 11 and a high C2H2/C2H4 selectivity of 4.8 at 273 K. Actual breakthrough experiments further demonstrate that UPC-22 is a promising potential adsorbent for C2H2/C2H4 separation with a C2H4 productivity of 1.07 mmol g(-1). Grand canonical Monte Carlo simulation and density functional theory indicate that the unsaturated Ni-II sites and uncoordinated carboxylate groups with an additional contribution from pi MIDLINE HORIZONTAL ELLIPSIS pi packing between aromatic rings provide stronger multipoint interactions with C2H2 over C2H4. This study offers practical guidance to fabricate durable materials for C2H2/C2H4 separation in real industrial scenarios.