A Propeller-Like Ligand-Directed Construction of a Tetranuclear Cerium-Organic Framework for Single-Step Ethylene Purification from Ternary C2 Mixtures

The efficient single-step purification of ethylene from ternary C-2 mixtures containing ethane and acetylene is challenging and demanding. Herein, we introduce a novel cerium-based metal-organic framework (MOF) of Ce-NTB-rtk synthesized via a ligand-conformer strategy. The Ce-NTB-rtk features a rare tetranuclear cerium cluster and 2D kgd layers pillared by a 3D rtl framework concomitant with an extraordinary (3,3,12)-c network. The compound encompasses microporous cavities replete with a nonpolar microenvironment. Gas sorption and breakthrough experiments demonstrate its superior affinity for C2H6 and C2H2 over C2H4, enabling effective single-step ethylene purification. Computational simulations reveal that preferential adsorptions are facilitated by different interaction strengths of C-H<middle dot><middle dot><middle dot>O hydrogen bonds. The performance of Ce-NTB-rtk in separation selectivity and regeneration capacity makes it a promising candidate for sustainable and cost-effective ethylene purification, showcasing the potential of MOFs in advanced gas separation applications.