Pore-Structure Control in Metal-Organic Frameworks (MOFs) for Capture of the Greenhouse Gas SF 6 with Record Separation.

In the electronics industry, the efficient recovery and capture of sulfur hexafluoride (SF 6 ) from SF 6 /N 2 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 SF 6 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 SF 6 gas. Ni(ina) 2 exhibits the highest SF 6 /N 2 selectivity (375.1 at 298 K and 1 bar) and ultra-high SF 6 uptake capacity (53.5 cm 3  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 SF 6 -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.