Cost-Effective Heptanuclear-Cluster-Based MOF for C₂H₂ Capture and One-Step C₂H₄ Purification from Ternary C₂...

In pursuit of cost-efficient adsorbent materials for capturing acetylene (C₂H₂) from mixtures of C₂ hydrocarbons and CO₂, we have designed a novel 3D framework Co7-Me·S using inexpensive isonicotinic acid (Hina) and methyl-modified isophthalic acid (H₂Me-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 C₂ hydrocarbon molecules. Breakthrough tests and GCMC simulations confirm that the activated Co7-Me can capture C₂H₂ molecules from C₂H₂/C₂H₄, C₂H₂/CO₂, and C₂H₂/C₂H₄/CO₂ mixtures and simultaneously capture C₂H₂ and C₂H₆ from a three-component C₂ hydrocarbon mixture, achieving one-step purification of C₂H₄. Moreover, the successful acquisition of single-crystal structure data with C₂H₂ guest molecules further confirmed the material's high selectivity for C₂H₂ guest molecules.