Cost-Effective Heptanuclear-Cluster-Based MOF for C 2 H 2 Capture and One-Step C 2 H 4 Purification from Ternary C 2 Hydrocarbon Mixtures

In pursuit of cost-efficient adsorbent materials for capturing acetylene (C 2 H 2 ) from mixtures of C 2 hydrocarbons and CO 2, we have designed a novel 3D framework Co7-Me·S using inexpensive isonicotinic acid (Hina) and methyl-modified isophthalic acid (H 2 Me-ip) as mixed linkers under hydrothermal synthesis conditions. Co7-Me·S exhibits excellent air and water stability. Its abundant carboxylate oxygen atoms and coordinated water molecules can form multiple hydrogen bonds with C 2 hydrocarbon molecules. Breakthrough tests and GCMC simulations confirm that the activated Co7-Me can capture C 2 H 2 molecules from C 2 H 2 /C 2 H 4, C 2 H 2 /CO 2, and C 2 H 2 /C 2 H 4 /CO 2 mixtures and simultaneously capture C 2 H 2 and C 2 H 6 from a three-component C 2 hydrocarbon mixture, achieving one-step purification of C 2 H 4 . Moreover, the successful acquisition of single-crystal structure data with C 2 H 2 guest molecules further confirmed the material’s high selectivity for C 2 H 2 guest molecules.