CO adsorption at nitrogen-doped carbons prepared by KCO activation of urea-modified coconut shell.

This article reports on the synthesis and characterization of porous nitrogen-doped carbons synthesized by carbonization of coconut shell followed by urea modification and KCO activation. The as-synthesized samples were carefully characterized by various techniques. This series of samples demonstrate high CO uptake at 1bar, up to 3.71mmol/g at 25°C in addition to 5.12mmol/g at 0°C. Furthermore, these sorbents possess fast CO adsorption kinetics, stable reusability, moderate heat of CO adsorption, reasonable CO/N selectivity, and high dynamic CO capture capacity under simulated flue gas conditions. It is found that, in addition to nitrogen content and narrow micropore volume, the pore size distribution of narrow micropore also plays a major role in determining the CO capture capacity under ambient condition. This work is intended to provide useful information and to inspire ways to develop new carbonaceous sorbents for removing CO from combustion flue gas.