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

Abstract

Nitrogen-doped microporous carbons were fabricated by a simple chemical activation strategy in which chitosan and K2CO3 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 K2CO3/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 CO2 capture and demonstrated excellent CO2 uptake performances. In particular, the sample prepared at 635°C with K2CO3/chitosan ratio=2 shows a CO2 uptake as high as 3.86mmolg−1 at 25°C, 1atm. Furthermore, the CO2 uptake remains almost constant in five consecutive adsorption–desorption cycles, indicating this material has great stability and recyclability as a CO2 sorbent. In addition, an extraordinary separation selectivity against N2 (CO2/N2 selectivity of ca. 21) was also observed.