Efficient in-situ conversion of low-concentration carbon dioxide in exhaust gas using silver nanoparticles in N-heterocyclic carbene polymer

Abstract

Efficient utilizing CO₂ is crucial approaches in achieving carbon neutralization. One of the challenges lies in the in-situ conversion of low concentration CO₂ found in waste gases. This study introduces a novel heterogeneous catalyst known as silver nanoparticles in porous N-heterocyclic carbene polymer (Ag@POP-NL-3). The catalyst is synthesized via a streamlined pre-coordination method. Ag@POP-NL-3 exhibits uniform distribution of silver nanoparticles, a porous structure and nitrogen activation groups. It demonstrates high efficiency and selectivity in absorbing and activating CO₂ and enabling the conversion of low concentration CO₂ (30 vol%) from lime kiln waste gas into cyclic carbonate under mild conditions. This catalytic system achieves both CO₂ capture and resource utilization of CO₂ simultaneously, effectively fixing low-concentration CO₂ from waste gases into C₂₊ valuable chemicals. This approach elegantly addresses two goals in one solution.

Keywords: Carbon dioxide utilization; Cyclic carbonate; Lime kiln waste gas; N-heterocyclic carbene polymer; Silver nanoparticles.