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

Abstract

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.