Post-synthetic fluorination of Scholl-coupled microporous polymers for increased CO2 uptake and selectivity

Abstract

We report a facile, one-step post-synthetic fluorination method to increase the CO₂ capacity and CO₂/N₂ selectivity of porous organic Scholl-coupled polymers. All of the fluorinated polymers that we synthesised showed increases in CO₂/N₂ IAST selectivity and CO₂ isosteric heat; almost all materials also showed an increase in absolute CO₂ uptake. Our best-performing material (SC-TPB F) demonstrated a CO₂ capacity and CO₂/N₂ selectivity of 3.0 mmol g⁻¹ and 26 : 1, respectively, at 298 K—much higher than the corresponding non-fluorinated polymer, SC-TPB. This methodology might also be applicable to other polymer classes, such as polymers of intrinsic microporosity, thus providing a more general route to improvements in CO₂ capacity and selectivity.