A new TIFSIX anion pillared metal organic framework with abundant electronegative sites for efficient C2H2/CO2 separation

Separation of acetylene (C2H2) from carbon dioxide (CO2) is important in industry to produce high purity C2H2 but challenged by the close physical properties. Herein, a novel microporous TIFSIX anion pillared metal organic framework ZNU-7 with abundant electronegative sites was prepared for efficient C2H2/CO2 adsorption separation. The non-coordinating fluorine atoms in the large pores selectively capture C2H2 from CO2 by hydrogen bonding. The C2H2 uptake capacity on ZNU-7 is as high as 92.1 cm(3) g(-1), over 2.5 fold of the CO2 uptake. The modest C2H2 adsorption heat of 35.3 kJ mol(-1) allows the facile desorption and regeneration of ZNU-7. The much stronger binding of C2H2 compared to CO2 was further revealed by DFT calculations. The practical separation ability was confirmed by breakthrough experiments using C2H2/CO2 gas mixtures with good recyclability. The dynamic separation factor of 3.0 for an equimolar C2H2/CO2 mixture is comparable to those of many benchmark materials.

Automated summary

Researchers have successfully prepared a novel microporous compound ZNU-7, which shows excellent adsorption separation ability for acetylene and carbon dioxide. It has high adsorption capacity, easy desorption and regeneration properties.