MOF‐on‐MOF Core–Shell Heterostructure With Synergistic Porous Interface for Highly Efficient Propane/Propylene Separation

Propylene is one of the most important industrial chemicals, while energy-efficient separation of propylene from the propane/propylene mixtures remains challenging. Conventional metal-organic frameworks (MOFs) with tunable pore structures enable selective adsorption, yet they typically suffer from an intrinsic trade-off between uptake capacity and selectivity. This work reports a Ni-MOF-74@ZU-609 MOF-on-MOF core-shell heterostructure that exhibits both high adsorption capacity and selectivity, arising from the synergistic interface between the integrated Ni-MOF-74 adsorptive core and the ZU-609 separation shell. Dynamic breakthrough experiments show that the interface-optimized Ni-MOF-74@ZU-609 core-shell heterostructure exhibits ultrahigh dynamic selectivity (5.51) and high dynamic capacity (1.14 mmol g^-1) for C₃H₆ at 298 K and 1 bar, outperforming either of the pristine MOFs, which further confirms the efficacy of the interfacial effect. This study demonstrates that precise interfacial engineering in MOF heterostructures successfully overcomes the long-suffered capacity-selectivity trade-off, thereby establishing a versatile design platform for high-performance gas separation materials.