Achieving Record C2H2 Packing Density for Highly Efficient C2H2/C2H4 Separation with a Metal‐Organic Framework Prepared by a Scalable Synthesis in Water

Abstract Adsorptive C 2 H 2 /C 2 H 4 separation using metal–organic frameworks (MOFs) has emerged as a promising technology for the removal of C 2 H 2 (acetylene) impurity (1 %) from C 2 H 4 (ethylene). The practical application of these materials involves the optimization of separation performance as well as development of scalable and green production protocols. Herein, we report the efficient C 2 H 2 /C 2 H 4 separation in a MOF, Cu(OH)INA (INA: isonicotinate) which achieves a record C 2 H 2 packing density of 351 mg cm −3 at 0.01 bar through high affinity towards C 2 H 2 . DFT (density functional theory) calculations reveal the synergistic binding mechanism through pore confinement and the oxygen sites in pore wall. The weakly basic nature of binding sites leads to a relatively low heat of adsorption (Q st ) of approximately 36 kJ/mol, which is beneficial for material regeneration and thermal management. Furthermore, a scalable and environmentally friendly synthesis protocol with a high space‐time yield of 544 kg m −3 day −1 has been developed without using any modulating agents. This material also demonstrates enduring separation performance for multiple cycles, maintaining its efficacy after exposure to water or air for three months.