(716e) CO2 Capture Using Highly Porous N-Doped Carbons Impregnated with Sodium

 This talk presents the selective CO₂ uptake capacity of sodium-impregnated and N-doped carbon sorbents (SNSs). The SNSs were synthesized by a two-step process of KOH activation of polyacrylonitrile (PAN) and subsequent NaOH impregnation of the activated N-doped carbons. Especially, SNS2-20 synthesized with the ratio of KOH to PAN equal to 2 at 700 °C and 20 wt% NaOH based on the mass of PAN exhibited a maximum CO₂ uptake of 6.84 and 4.48 mmol g^-1 at ambient pressure, and an exceptional CO₂ capacity of 3.03 and 1.90 mmol g^-1 under flue gas conditions (0.15 bar CO₂) at 0 and 25 °C, respectively. These enhanced CO₂ capture performance is mainly due to the existence of narrow micropores (< 0.7 nm) and intrinsic N contents together with the strong basic sites generated by NaOH impregnation. In addition, it showed CO₂/N₂ selectivities of 59.5, 68.9 and 79.4 at 0, 25 and 50 °C for the gas mixture (CO₂:N₂=15:85). We will demonstrate the unaltered CO₂ uptake subject to even consecutive adsorption–desorption cycle experiments at 25 °C. Considering its simple preparation and superior CO₂ capture properties, SNS2-20 might be a promising sorbent for practical applications of CO₂ capture and storage.