Pore‐Structure Control in Metal–Organic Frameworks (MOFs) for Capture of the Greenhouse Gas SF6 with Record Separation

• Published in: Angewandte Chemie International Edition 2022-08, Vol.61 (33), p.e202207066-n/a
• Main Authors: Wang, Shao‐Min, Mu, Xuan‐Tong, Liu, Hao‐Ran, Zheng, Su‐Tao, Yang, Qing‐Yuan
• Format: Article
• Language: English
• Subjects: Copper; Crystal structure; Electronics industry; Fluorinated Gas; Greenhouse gases; Industrial applications; Metal-organic frameworks; Pore Size Control; Selectivity; Separation; SF6/N2 Separation; Sulfur; Sulfur hexafluoride
• ISSN: 1433-7851; 1521-3773
• DOI: 10.1002/anie.202207066

In the electronics industry, the efficient recovery and capture of sulfur hexafluoride (SF6) from SF6/N2 mixtures is of great importance. Herein, three metal–organic frameworks with fine‐tuning pore structures, Cu(peba)2, Ni(pba)2, and Ni(ina)2, were designed for SF6 capture. Among them, Ni(ina)2 has perfect pore sizes (6 Å) that are comparable to the kinetic diameter of sulfur hexafluoride (5.2 Å), affording the benchmark binding affinity for SF6 gas. Ni(ina)2 exhibits the highest SF6/N2 selectivity (375.1 at 298 K and 1 bar) and ultra‐high SF6 uptake capacity (53.5 cm3 g−1 at 298 K and 0.1 bar) at ambient conditions. The remarkable separation performance of Ni(ina)2 was verified by dynamic breakthrough experiments. Theoretical calculations and the SF6‐loaded single‐crystal structure provided critical insight into the adsorption/separation mechanism. This porous coordination network has the potential to be used in industrial applications. The metal–organic framework (MOF) Ni(ina)2 has pore sizes (6 Å) that are perfectly compatible with the kinetic diameter of sulfur hexafluoride (5.2 Å), affording the benchmark binding affinity for this potent greenhouse gas that is used in the electronics industry.