Chitosan derived nitrogen-doped microporous carbons for high performance CO2 capture

Nitrogen-doped microporous carbons were fabricated by a simple chemical activation strategy in which chitosan and K 2 CO 3 were employed as the precursor and activation agent, respectively. The textural and chemical properties of the porous carbons could be easily tuned by changing the ratio of K 2 CO 3 /chitosan and activation temperature. Due to their large pore volume , well-defined microporosity and relatively high nitrogen content, these porous carbons were applied as adsorbents for CO 2 capture and demonstrated excellent CO 2 uptake performances. In particular, the sample prepared at 635   °C with K 2 CO 3 /chitosan ratio   =   2 shows a CO 2 uptake as high as 3.86   mmol   g −1 at 25   °C, 1   atm. Furthermore, the CO 2 uptake remains almost constant in five consecutive adsorption–desorption cycles, indicating this material has great stability and recyclability as a CO 2 sorbent . In addition, an extraordinary separation selectivity against N 2 (CO 2 /N 2 selectivity of ca. 21) was also observed.