Atom-level interaction design between amines and support for achieving efficient and stable CO<sub>2</sub> capture.

Sun, Xin; Shen, Xuehua; Wang, Hao; Yan, Feng; Hua, Jiali; Li, Guanghuan; Zhang, Zuotai · Nat Commun · 2024

basic_science · Level V

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Abstract

Amine-functionalized adsorbents offer substantial potential for CO<sub>2</sub> capture owing to their selectivity and diverse application scenarios. However, their effectiveness is hindered by low efficiency and unstable cyclic performance. Here we introduce an amine-support system designed to achieve efficient and stable CO<sub>2</sub> capture. Through atom-level design, each polyethyleneimine (PEI) molecule is precisely impregnated into the cage-like pore of MIL-101(Cr), forming stable composites via strong coordination with unsaturated Cr acid sites within the crystal lattice. The resulting adsorbent demonstrates a low regeneration energy (39.6 kJ/mol<sub>CO2</sub>), excellent cyclic stability (0.18% decay per cycle under dry CO<sub>2</sub> regeneration), high CO<sub>2</sub> adsorption capacity (4.0 mmol/g), and rapid adsorption kinetics (15 min for saturation at 30 °C). These properties stem from the unique electron-level interaction between the amine and the support, effectively preventing carbamate products' dehydration. This work presents a feasible and promising cost-effective and sustainable CO<sub>2</sub> capture strategy.