Nitrogen-enriched microporous carbon derived from sucrose and urea with superior CO2 capture performance

Abstract

Nitrogen-enriched carbon with well-developed microporosity and superior CO2 adsorption capacity was prepared by KOH activation of a nitrogen-containing polymer obtained by heating sucrose and urea. The nitrogen content, microporosity, and surface area of the activated carbon depend on the concentration of urea and KOH. The maximum surface area, total pore volume, and nitrogen content of the activated carbon produced were 2366 m2/g, 1.16 cm3/g, and 10.5 wt%, respectively. A maximum CO2 adsorption capacity of 7.0 mmol/g was achieved at 0 °C and 1 bar. The CO2 adsorption capacity of 0.70 mmol/g from dry air containing 400 ppm of CO2 was the highest reported in the category of carbonaceous materials. The CO2 adsorption capacity of all the prepared carbon materials correlated well with the nitrogen content and microporosity. CO2 adsorption on the activated carbon materials showed excellent selectivity over nitrogen, with one of the highest selectivity factors of 38; hence, it is an ideal candidate for CO2 removal from flue gases.