Quaternary ammonium-functionalized polysulfone sorbent: Toward a selective and reversible trap-release of CO2

A novel good performing and selective polymeric sorbent has been synthesized by chemical modification of eco-friendly and inexpensive polysulfone through introduction of quaternary ammonium pendant groups (qPSU). The self-standing film conjugated outstanding thermo-mechanical resistance with high selectivity of adsorption for CO2 over methane, fast capture kinetics and very good stability over multiple adsorption-desorption cycles. Worth notes, the qPSU sorbent exhibited absorption capacity up to 2.21 mmol g-1 under simulated flue gas conditions (humid 6 % CO2, 20 % relative humidity and ambient pressure) and one of the highest amine efficiency reported to date for low-temperature and low-pressure CO2 sorbents. The maximum adsorption capacity can be completely restored under mild conditions (50 °C in pure N2 for 20 min), with only 60.3 kJ mol-1 consumed during sorbent regeneration. 13C NMR characterization revealed carbon dioxide is chemisorbed via formation of bicarbonate ions. The approach may be further extended to a wide range of polymeric systems, and thus might open up new avenues in the development of advanced carbon dioxide sorbents.