One-step synthesis of highly porous nitrogen doped carbon from the direct pyrolysis of potassium phthalimide for CO2 adsorption

Abstract In the current work, we reported the synthesis of nitrogen doped carbons (NDCs) with a very convenient one-step strategy. Highly porous NDCs were successfully prepared from the direct pyrolysis of potassium phthalimide at 600−900 °C. The obtained carbon had a high specific surface area (2053 m2/g) and pore volume (1.14 cm3/g) after pyrolysis at 900 °C. The nitrogen content of the carbon was 3.3–9.1 wt%, and decreased with the increase of pyrolysis temperature. The combination of high porosity and nitrogen content made the synthesized NDCs attractive CO2 adsorbents. At 25 °C, the carbon exhibited CO2 uptakes of 1.1 mmol/g at 0.15 bar, and 3.4 mmol/g at 1 bar. The experiment results also revealed a linear relationship between the uptake at 0.15 bar and the CO2/N2 adsorption selectivity. Small micropores and nitrogen containing functionalities had decisive effects on these properties.