A rationally designed amine absorbent for CO₂ capture via proton transfer: Beyond the absorption–desorption trade‐off

Amine‐scrubbing‐based chemical absorption is an effective and industrialized technology for CO 2 capture, but the challenge lies in developing efficient and energy‐saving absorbents. Here we present a rationally designed amine absorbent, N ‐(2‐hydroxypropyl)‐ N ‐ethylethylenediamine (HPEEDA), featuring simultaneous functionalized ethyl and hydroxypropyl groups on a tertiary amine. Experimental results demonstrate that HPEEDA exhibits high efficiency in both CO 2 absorption and desorption, while offering great energy‐saving advantages during regeneration. The structure–activity relationship between HPEEDA and CO 2 capture is revealed through the systematic examination of the disassembled HPEEDA blends. Quantitative experiments and theoretical calculations elucidate the CO 2 capture mechanism of HPEEDA, highlighting the critical role of intermolecular proton transfer in promoting CO 2 capture. This rationally designed amine absorbent that breaks the CO 2 absorption–desorption trade‐off is expected to advance underway efforts toward large‐scale CO 2 capture.