Quaternary functionalized mesoporous adsorbents for ultra-high kinetics of CO capture from air.

Obstacles to widespread deployments of direct air capture of CO (DAC) lie in high material and energy costs. By grafting quaternary ammonium (QA) functional group to mesoporous polymers with high surface area, a unique DAC adsorbent with moisture swing adsorption (MSA) ability and ultra-high kinetics was developed in this work. Functionalization is designed for efficient delivery of QA group through mesopores to active substitution sites.

Spontaneous Cooling Absorption of CO by a Polymeric Ionic Liquid for Direct Air Capture.

A polymeric ionic liquid (PIL), with quaternary ammonium ions attached to the polymer matrix, displays CO affinity controlled by moisture. This finding led to the development of moisture swing absorption (MSA) for direct air capture of CO. This work aims to elucidate the role of water in MSA.

Theoretical studies on CO2 capture behavior of quaternary ammonium-based polymeric ionic liquids.

Quaternary ammonium-based polymeric ionic liquids (PILs) are novel CO2 sorbents as they have high capacity, high stability and high binding energy. Moreover, the binding energy of ionic pairs to CO2 is tunable by changing the hydration state so that the sorbent can be regenerated through humidity adjustment. In this study, theoretical calculations were conducted to reveal the mechanism of the humidity swing CO2 adsorption, based on model compounds of quaternary ammonium cation and carbonate anions.