Highly efficient carbon dioxide capture in diethylenetriamine-appended porous organic polymers: Investigation of structural variations of chloromethyl monomers

Abstract

Post-combustion CO2 capture from large point sources has been proposed as a promising technology to prevent growth of the level of atmospheric CO2 and thus restrict the progress of global warming. However, CO2 capture technology is economically unfeasible at present due to the high cost and large energy penalty. Therefore, the development of cost-effective CO2 capture technologies has attracted keen interest. Herein, we develop a series of amine-functionalized adsorbents via one-step amine grafting of cost-effective porous polymers containing unreacted chloromethyl groups, which are prepared from five di- or trichloromethyl monomers via Friedel-Crafts alkylation. Among the adsorbents prepared, PTPDETA possesses the highest CO2 uptake capacity and CO2/N-2 selectivity owing to the highest amine loading. In contrast, the highly porous adsorbent PBP-DETA presents the fastest adsorption kinetics but poorest CO2 capture performance. Nevertheless, subsequent breakthrough experiments revealed that all amine-functionalized adsorbents retain attractive CO2 adsorption properties under dynamic flow conditions even in the presence of moisture.