A well-defined nitro-functionalized aromatic framework (NO2-PAF-1) with high CO2 adsorption: synthesis via the copper-mediated Ullmann homo-coupling polymerization of a nitro-containing monomer

Abstract

A well-defined nitro group functionalized porous aromatic framework (NO₂-PAF-1) was synthesized via a bottom-up strategy using a copper-mediated Ullmann reaction. The synthetic route is cost-efficient and robust for large scale preparation. The Brunauer–Emmett–Teller (BET) specific surface area of the obtained NO₂-PAF-1 is up to 610 cm² g⁻¹ with micro/mesoporosity. Its CO₂ uptake was measured to be higher than that of PAF-1 due to the strong interaction between the nitro groups and CO₂ molecules, proven by the enhanced isosteric heat of CO₂ adsorption (38.4 kJ mol⁻¹).