Hyper-crosslinked aromatic polymers with improved microporosity for enhanced CO2/N2 and CO2/CH4 selectivity

Abstract

Hypercrosslinked polymers for selective CO₂ capture have been successfully synthesized from highly rigid contorted blocks via a low-cost versatile strategy. Such amorphous materials with improved porosities achieve high specific surface areas of up to 1616 m² g⁻¹ and substantially improved pore volumes (1.53 cm³ g⁻¹). The polymer networks feature hierarchically porous structures ranging from ultramicropores to mesopores (0.50 to 3.80 nm) as well as high physicochemical stability. They can uptake 15.9 wt% CO₂ at 273 K/1 bar, surpassing nearly all polymers of intrinsic microporosity (PIMs) and most known hypercrosslinked polymers (HCPs). The abundant ultramicropores with pore diameters centered at around 0.50 nm allow selective CO₂ uptake against N₂ (ideal selectivity: 69.7) and CH₄ (15.8). These results are significant for molecular design and emphasize the importance of utilizing rigid contorted blocks to build hierarchically porous networks for effective CO₂ capture applications.