Statistical Insights into MOF Design: A Pillar-Layered MOF with High-Density N/O Sites for One-Step C2 Separation

Although the one-step separation of ethylene from C2 hydrocarbons remains a significant challenge, one-step C2 separation provides a revolutionary breakthrough in cost savings and efficient energy utilization. Recent advances in metal-organic frameworks (MOFs) for achieving one-step C2 separation have been widely recognized. In this work, for the first time, the potential relationship between the structure and properties of MOF materials previously used for one-step C2 separation was revealed from a mathematical statistical perspective. Additionally, the importance of N/O sites in enhancing the selectivity of C₂H₆/C₂H₄ separation is elucidated as a supplementary finding. Guided by the above findings, a pillar-layered MOF (JLU-MOF167) was synthesized using a mixed-ligand strategy. The unprecedented layer structure, composed of triazole units and multiple Cd units, provides an optimal thickness that creates a large number of N/O sites. Simultaneously, the tortuous channels between the pillars ensure sufficient interaction space between the molecules and the framework. The excellent structural design enables JLU-MOF167 to exhibit outstanding performance in both C₂H₂/C₂H₄ and C₂H₆/C₂H₄ separations as well as dynamic separation capabilities. Furthermore, theoretical calculations confirm the critical role of high-density N/O sites in facilitating one-step C2 separation.