Carbonyl functionalized hyper-cross-linked polymers for CO₂ capture

Two hyper-cross-linked polymers (HCPs) were readily prepared through one-pot Friedel-Crafts reaction using methylene and carbonyl as the rigid cross-linking bridges. Unexpectedly, the methylene cross-linked PDV-pc-1 (686 m²/g and 0.37 cm³/g, respectively) owned a little higher Brunauer-Emmett-Teller surface area and pore volume than the carbonyl cross-linked PDV-pc-2 (635 m²/g and 0.33 cm³/g, respectively), while PDV-pc-2 had a higher CO₂ uptake (86 mg/g) than PDV-pc-1 (64 mg/g), the introduced carbonyl groups and the better microporosity were the main reasons. Specially, the CO₂ uptake had a good linear correlation with the ultramicropores (d < 1.0 nm) (R² = 0.998). In particular, the CO₂ uptake of the direct carbonized PDVC-2 (57 mg/g) was almost identical to the KOH-activated carbonized PDVC-KOH (62 mg/g) at 0.15 bar in spite of its much lower Brunauer-Emmett-Teller surface area, proving that PDVC-2 had a good prospect of CO₂ capture from harsh flue gas conditions.