Construction of Multiple Nonpolar SF<sub>6</sub> Nano‐Traps by Highly Stable Pyrazole‐Based MOFs for SF<sub>6</sub> Recovery
Qichen Fan, Jinze Yao, Siyao Zhao, Xingbei Wu, Jiajin Huang, Haoyuan Luo, Qibin Xia
Abstract
Abstract Sulfur hexafluoride (SF 6 ), widely used in electric power systems, is one of the most potent greenhouse gases. Efficient separation of SF 6 /N 2 by adsorptive separation technology based on porous materials is of great significance in the industry yet remains a daunting challenge. Herein, a novel strategy is introduced to construct unique pore channels with multiple SF 6 nano‐traps by precisely selecting bipyrazole ligands to design the nonpolar surface of microporous metal−organic frameworks (MOFs), which significantly enhances the material's affinity for SF 6 . A series of ultra‐stable bipyrazole‐based MOFs, M(BPZ) (M═Co, Ni, Zn), are synthesized and investigated. Among these three materials, Co(BPZ) and Zn(BPZ) show excellent SF 6 uptakes of 2.47 and 2.39 mmol g −1 at 298 K and 0.1 bar while Co(BPZ) exhibits the highest SF 6 /N 2 (10/90, v/v) IAST selectivity of 748. Breakthrough experiments reveal that SF 6 /N 2 mixtures can be efficiently separated by Co(BPZ) with a high SF 6 (≥99.5 %) productivity of 46.1 L kg −1 . Theoretical calculations suggest that SF 6 preferably adsorbs in the channels through multiple S−F··· π (pyrazole rings) van der Waals interactions. This work provides a straightforward approach for exploring adsorbents in efficient SF 6 /N 2 separation.