A Scalable Pore-space-partitioned Metal-organic Framework Powered by Polycatenation Strategy for Efficient Acetylene Purification.

Efficient separation of acetylene (CH) from carbon dioxide (CO) and ethylene (CH) is a significant challenge in the petrochemical industry due to their similar physicochemical properties. Pore space partition (PSP) has shown promise in enhancing gas adsorption capacity and selectivity by reducing pore size and increasing the density of guest binding sites. Herein, we firstly employ the 2D→3D polycatenation strategy to construct a PSP metal-organic framework (MOF) Ni-dcpp-bpy, incorporating functional N/O sites to enhance CH purification. The polycatenated framework with optimized pore size and regularity, exhibiting significant improvements over traditional PSP MOFs by resolving the critical contradiction of balancing CH uptake (98.5 cm g at 298 K, 100 kPa) and selectivity of CH/CO (3.4), CH/CH (5.9), and CH/CH (96.4) in a MOF. Breakthrough experiments confirm high-purity CH (>99.9 %) and high CH productivity from binary and ternary mixtures. Notably, Ni-dcpp-bpy exhibits excellent water stability, scalability, and regenerability after 20 cycles for separating CH/CO. Theoretical calculations verify that the strong binding of CH is mainly attributed to the C-H⋅⋅⋅O/N interactions between host Ni-dcpp-bpy and guest CH molecules. The polycatenation strategy not only improved industrial CH purification efficiency but also enriched the design diversity of customized MOFs for other gas separation applications.