Effect of ZnCl₂ activation on CO₂ adsorption of N-doped nanoporous carbons from polypyrrole

In this study, N-doping nanoporous carbons (NNCs) were prepared from polypyrrole (PPY) by ZnCl₂ activation. The activation process was carried out under set conditions (PPY/ZnCl₂=1/4) at 300–800 °C for 2 h. With increasing activation temperature, the specific surface area and total pore volume of the NNCs increased significantly from 539 m²/g (300 °C) to 1268 m²/g (700 °C) and from 0.245 cm³/g (300 °C) to 0.561 cm³/g (700 °C), respectively. In addition, the use of PPY carbon precursors allowed the integration of high N content (9.28 wt%) and resulted in a large narrow micropore distribution (<1 nm) in the prepared NNCs. The CO₂ adsorption isotherms showed that PZ-600 exhibited the best CO₂ adsorption capacity of 167 mg/g at 1 bar and 25 °C when the activation temperature was 600 °C. - Graphical abstract: CO₂/298 K adsorption/desorption isotherms of the N-enriched porous carbons. - Highlights: • N-doping nanoporous carbons were prepared from polypyrrole by ZnCl₂ activation. • Through ZnCl₂ activation, the specific surface area and total pore volume increased. • PZ-600 exhibited the best CO₂ adsorption capacity of 167 mg/g at 1 bar and 25 °C