Metal‐Organic Frameworks for Breakthrough Separation of 2‐Butene Isomers with High Dynamic Selectivity and Capacity

Abstract

AbstractDeveloping porous sorbents represents a potential energy‐efficient way for industrial gas separation. However, a bottleneck for reducing the energy penalty is the trade‐off between dynamic adsorption capacity and selectivity. Herein, we showed this problem can be overcome by modulating the kinetic and thermodynamic separation behaviours in metal–organic frameworks for sieving 2‐butene geometric isomers, which are desired for upgrading the raffinates to higher value‐added end products. We found that the iron‐triazolate framework can realize the selective shape screening of 2‐butene isomers assisted by electrostatic interactions at the pore apertures. Further introducing uncoordinated N binding sites by ligand substitution lowered the gas diffusion barrier and greatly boosted the dynamic separation performance. In breakthrough tests under ambient conditions, trans‐2‐C4H8 can be efficiently separated from cis‐2‐C4H8 with a record capacity of 2.10 mmol g−1 with high dynamic selectivity of 2.39.