A promising adsorbent of Quaternary amine based materials is synthesized for CO₂ air capture, and the effect of humidity, temperature and micropore on CO₂ adsorption kinetics is analyzed. The adsorbents with microporous structure showed much higher adsorption kinetics than that with macroporous structure, and the highest kinetics performance of CO₂ adsorption ever reported is obtained.

Abstract

Quaternary amine(QA)-functionalized adsorbents using moisture swing method are demonstrated to have vast application prospect in capturing CO₂ from the ambient air. However, the poor kinetic performance and limited sorbents remain a great challenge. In this work, the porous resins were screened and membrane with controllable porous structure was designed for CO₂ air capture, and the effects of the varieties of QA-based resins and external environmental conditions (humidity and temperature) on CO₂ adsorption performance were quantitatively investigated. The results show that the kinetic performance of porous resins are far superior to the existing QA-based direct air capture(DAC) materials, and the half-time of D290 type membrane is only 102 s, much less than that of gelatinous resin, which is about 2400 s. The effect of microporous structure on CO₂ adsorption rate increases with the increase of humidity, while only slightly effect was found on macroporous adsorbents. The research results can provide basic data for the application of CO₂ capture in different occasions.