Design and synthesis of different sized polyhedral channel MOF materials for the separation of CO2/N2.

• Fractal polyhedral MOFs (Cu-TATB) is synthesized for CO 2 /N 2 separation. • Small-sized pores can capture CO 2 , while large-sized pores facilitate N 2 escape. • Different sized channels successfully achieving the goal of gas separation. A fractal polyhedral pore structural MOFs (Cu-TATB) is synthesized from the coordination of tridentate ligands (H 3 TATB) and Cu 4 clusters. This material is characterized by single crystal X-ray diffraction, powder X-ray diffraction, thermogravimetric analysis. The structure contains two different pore structures, including closed octahedral cages and open tetrakaidecahedron cages. The material has been successfully utilized for the separation of CO 2 /N 2 due to the fractal structure of the channel with different pore sizes. Under optimized temperature, Cu-TATB adsorbed a large amount of CO 2 and only negligible amount of N 2 , and the selectivity reaches 27. Breakthrough experiments demonstrated that this material can efficiently separate N 2 and CO 2. This structure further demonstrates the infinite potential of 3D MOFs with diverse pore structures in applications such as CO 2 adsorption and separation. [ABSTRACT FROM AUTHOR]