A microporous framework with aromatic pores for one-step purification of C2F6 from CF3CH2F/CF3CHF2/C2F6 mixture

Abstract

Separating C2F6 from CF3CH2F/CF3CHF2/C2F6 is of great importance since electronic grade C2F6 is an important plasma etching gas that can be used for surface cleaning of electronic devices, as well as microelectronics, fiber optic cables and solar cells. Herein, a four-fold intermingled MOF material Ni(pba)2 was constructed, which has a high selectivity of CF3CH2F/C2F6 (38.8) and CF3CHF2/C2F6 (19.8). Breakthrough experiments show that high-purity C2F6 can not only be obtained from the binary CF3CHF2/C2F6 (5/95, v/v) and CF3CH2F/C2F6 (5/95, v/v) mixtures but also can be directly collected from ternary CF3CH2F/CF3CHF2/C2F6 (5/5/90, v/v/v) mixture with a high productivity of 7.1 mol/kg. Additionally, it is found that Ni(pba)2 can maintain good separation performance under different conditions. Finally, the theoretical calculation results show that the interactions between C2F6 and the aromatic pores are significantly lower than those of CF3CHF2 and CF3CH2F, which leads to good C2F6 separation performance.