Observation of the wrapping mechanism in amine carbon dioxide molecular interactions on heterogeneous sorbents

Liquid, solvated amine based carbon capture is the core of all commercial or planned CO 2 capture operations. Despite the intense research, few have looked systematically into the nature of amine molecules and their CO 2 interaction. Here, we report a systematic introduction of linear ethylene amines on the walls of highly porous Davankov type network structures through simple bromination intermediates. Surprisingly, isosteric heats of CO 2 adsorption show a clear linear trend with the increase in the length of the tethered amine pendant groups, leading to a concerted cooperative binding with additional H-bonding contributions from the unassociated secondary amines. CO 2 uptake capacities multiply with the nitrogen content, up to an unprecedented four to eight times of the starting porous network under flue gas conditions. The reported procedure can be generalized to all porous media with the robust hydrocarbon framework in order to convert them into effective CO 2 capture adsorbents. CO 2 binds multiple amines if nearby, leading to higher heats of adsorption, a previously unknown observation.