One-pot carbonization enrichment of nitrogen in microporous carbon spheres for efficient CO2 capture

Nitrogen-enriched porous carbon spheres are synthesized through a one-pot carbonization process by decorating the as-made melamine-formaldehyde spheres with resorcinol and hexamethylenetetramine, exhibiting high surface areas of 518-828 m(2) g(-1) with a micropore size of 0.5-1.3 nm. Due to the successful incorporation of large amounts of highly dispersed N (4.3-10.8 wt%) into the carbon matrix, the synthesized microporous carbon spheres, having a large amount of narrow micropores (< 1.0 nm), show a good capacity to store CO2. At 1 atm, the equilibrium CO2 capture capacities of the obtained microporous carbons are in the range of 4.0-5.4 mmol g(-1) at 0 degrees C and 3.0-4.3 mmol g(-1) at 25 degrees C, revealing their great promise for practical CO2 capture applications. More importantly, the CO2 uptake as large as 2.76 mmol g(-1) can be obtained at 75 degrees C, suggesting the significant promise of the synthesized carbon materials for CO2 capture and separation.