Conjugated microporous copolymer networks with enhanced gas adsorption

A series of copolymerized conjugated microporous polymers (CP-CMPs) was synthesized by Suzuki cross-coupling copolymerization of 1,4-benzene diboronic acid with different ratios of comonomers of 1,3,6,8-tetrabromopyrene and 1,3,6,8-tetrabromocarbazole. These CP-CMPs are stable in common organic solvents and are thermally stable. The ratio of comonomers has a large effect on the pore properties of these CP-CMPs, such as the apparent Brunauer–Emmett–Teller (BET) specific surface area, micropore surface area, and micropore volume. CP-CMP5 copolymerized with 60 mol% 1,3,6,8-tetrabromocarbazole shows a high BET specific surface area of up to 2241 m2 g−1 and a high CO2 uptake of 4.57 mmol g−1 (1.13 bar/273 K) with a H2 uptake of 2.24 wt% (1.13 bar/77.3 K). These results demonstrate that copolymerization is an efficient strategy for tuning the pore properties of microporous organic polymers, and is promising for producing other microporous organic polymers with high porosity and CO2 uptake.