Efficient C₃H₆/C₃H₈ separation within a bifunctional ultramicroporous metal-organic framework with high purity and record packing density

The propylene/propane (C₃H₆/C₃H₈) separation is particularly challenging due to their highly similar physical properties, but of industrial importance. Herein, we report a bifunctional ultramicroporous metal-organic framework (Co-aip-pyz) with customized pore environment and selective binding sites for the challenging C₃H₆/C₃H₈ separation. Co-aip-pyz exhibits a good C₃H₆ uptake with an ultrahigh C₃H₆ packing density (931 g/L), as well as possesses a remarkable C₃H₆/C₃H₈ uptake ratio with 911% and distinguished C₃H₆/C₃H₈ selectivity (>104) at 298 K and 1.0 bar. Furthermore, Co-aip-pyz possesses a record high C₃H₆ packing density with 859 g/L at 313 K and 1.0 bar, which is unprecedented in the C₃H₆/C₃H₈ separation. Its high performance for the C₃H₆/C₃H₈ separation has been further confirmed by breakthrough experiments and molecular simulations. Combined with good stability, facilely synthesized procedure by low-cost precursors, record-high C₃H₆ packing density, as well as good C₃H₆/C₃H₈ separation performance, it highlights Co-aip-pyz as a benchmark adsorbent to address daunting challenge for industrial C₃H₆/C₃H₈ separation. This work provides valuable insights into constructing top-performing MOF materials for addressing the industrial separation challenges.