An atom-level interaction design between amine and support: achieving efficient and stable CO2 capture

Abstract

Amine-functionalized adsorbents hold great promise for CO2 capture due to their exceptional selectivity and diverse applications scenarios. However, their applications are impeded by low efficiency and unstable cyclic performance. Here, a novel amine-support system is synthesized to achieve an efficient and stable CO2 capture. Based on an atom-level design, each polyethyleneimine (PEI) molecule is precisely impregnated into cage-like pore of MIL-101(Cr), forming stable composites through strong coordination with unsaturated Cr acid sites in crystal internalization. The developed adsorbent exhibits low regeneration energy (39.6 kJ/molCO2), excellent cyclic stability (0.18% decay per cycle under dry CO2 regeneration) high CO2 adsorption capacity (4.0 mmol/g), and rapid adsorption kinetics (15 min for saturation at room temperature). These outstanding properties result from the unique electron-level interaction between amine and support, which prevents the dehydration of carbamate products. This work provides a feasible and promising strategy for cost-effective and sustainable CO2 capture.