Pyrene-derived benzimidazole-linked polymers (BILPs) have been prepared and evaluated for selective CO2 uptake and separation under pressure and vacuum swing conditions. Condensation of 1,3,6,8-tetrakis(4-formylphenyl)pyrene (TFPPy) with 3,6,7,10,11-hexaaminotriphenylene, 2,3,6,7,14,15 hexaaminotriptycene, and 3,3`diaminobenzidine afforded BILP-11, BILP-12 and BILP-13, respectively, in good yields. BILP-12 exhibits the highest specific surface area (SABET = 1497 m2 g-1) among all known BILPs and it also has very high CO2 uptake 5.06 mmol g-1 at 273 K and 1.0 bar. Initial slope selectivity calculations indicate that BILP-11 has high selectivity for CO2/N2 (103) and CO2/CH4 (11) at 273 K. IAST selectivity calculations of BILPs at 298 K also showed high CO2/N2 (31-56) and CO2/CH4 (6.6-7.6) selectivity levels. The isosteric heats of adsorption for CO2 fall in the range of 32 to 36 kJ mol-1 and were considerably higher than those of CH4 (16.1-21.7 kJ mol-1). More importantly, the performance of pyrene-based