Hypercrosslinked polymers (HCPs) synthesized by copolymerisation of p-dichloroxylene (p-DCX) and 4,4′-bis(chloromethyl)-1,1′-biphenyl (BCMBP) constitute a family of low density porous materials with excellent textural development. Such polymers show microporosity and mesoporosity and exhibit Brunauer–Emmett–Teller (BET) surface areas of up to 1970 m² g⁻¹. The CO₂ adsorption capacity of these polymers was evaluated using a thermogravimetric analyser (atmospheric pressure tests) and a high-pressure magnetic suspension balance (high pressure tests). CO₂ capture capacities were related to the textural properties of the HCPs. The performance of these materials to adsorb CO₂ at atmospheric pressure was characterized by maximum CO₂ uptakes of 1.7 mmol g⁻¹ (7.4 wt%) at 298 K. At higher pressures (30 bar), the polymers show CO₂ uptakes of up to 13.4 mmol g⁻¹ (59 wt%), superior to zeolite-based materials (zeolite 13X, zeolite NaX) and commercial activated carbons (BPL, Norit R). In addition, these polymers showed low isosteric heats of CO₂ adsorption and good selectivity towards CO₂. Hypercrosslinked polymers have potential to be applied as CO₂ adsorbents in pre-combustion capture processes where high CO₂ partial pressures are involved.

Different carbon materials were tested as precursors for the production of C O2 adsorbents. The chemical modification of the surface of the prepared adsorbents was studied by means of three different approaches: impregnation with amines, electrophilic aromatic substitution, and heat treatment in the presence of ammonia. The samples were chemically characterized and the porous texture was evaluated from the N2 adsorption isotherms at −196°C . The C O2 adsorption capacities of the adsorbents at 25 and 100°C were evaluated in a thermogravimetric analyzer. In general, the incorporation of basic nitrogen functionalities enhanced the C O2 capture capacities of the modified carbons, but this increase depended on the textural properties of the support and the surface modification methodology. C O2 adsorption capacities of up to 111 mg C O2 ∕g at room temperature were attained. All the tested samples were completely regenerated when subjected to heat treatment at 100°C under inert atmosphere.