Agar‐Derived Nitrogen‐Doped Porous Carbon for CO2 Adsorption

Abstract An efficient carbonaceous CO 2 adsorbent with doped nitrogen element is derived from agar. Agar was mixed with urea and the mixture was then carbonized. After chemical activation with KOH, nitrogen doped microporous carbon was obtained. The nitrogen content was up to 8.58 wt %, depending on the preparation conditions. The CO 2 adsorption properties, including the adsorption isotherms, the isosteric heat of adsorption and the adsorption selectivity were studied. The highest CO 2 uptake of 6.5 mmol g −1 (273 K, 1 bar) was achieved by a carbon activated at 600 °C with moderate nitrogen content, while the carbon activated at 550 °C exhibited the best CO 2 /N 2 selectivity of 37. The current work exploits the potential use of agar as carbon precursor for CO 2 adsorbent, and provides a convenient and effective approach to nitrogen doping.