Hierarchically Porous Hyper-Cross-Linked Porous Polymers with Enhanced Synergistic Effect for SF6/N2 Separation

A highly potent greenhouse gas, sulfur hexafluoride (SF 6 ), requires efficient capture from industrial SF 6 /N 2 mixtures. Herein, a series of benzene-rich hyper-cross-linked polymers (PPBx) were synthesized via a low-cost Friedel–Crafts alkylation reaction using α,α ′ -dichloro- p -xylene (DCX) and triphenylbenzene (TPB) at different molar ratios. The abundant benzene rings in the material enable strong F–π interactions with SF 6 , while the hierarchical micromesoporous structure ensures high adsorption capacity. Adsorption tests revealed that PPB1, fabricated at a DCX/TPB molar ratio of 3:1, achieved a remarkably high SF 6 uptake of 2.05 mmol/g at 298 K and 1 bar and an impressive SF 6 /N 2 ideal adsorbed solution theory selectivity of 120 at 298 K. In addition, the dynamic separation performance for SF 6 /N 2 was up to 1274.6 s/g, also demonstrating excellent properties under actual operating conditions. The PPB1 material also demonstrates excellent thermal stability and cycling performance. This work provides a cost-effective and highly efficient hyper-cross-linked polymeric adsorbent with high potential for industrial SF 6 separation and recovery.