Tailoring the pore structure modified with functional groups for superior CO2 adsorption capacity and the selectivity of separation

In this work, the ultra-uniform amidated nitrogen (N)-doped carbon sphere (ANG-Cs) adsorbent with different pore sizes and modified by kinds of functional groups was developed for efficient carbon dioxide (CO2) adsorption, simultaneously obtaining the excellent selectivity of CO2/N-2 from the simulated ultra-low emission flue gas. We fabricated the uniformly monodispersed glucose-based carbon microspheres via a creative ethanol-assisted hydrothermal method, and also systematically explored and discussed the relationship between porous structures functional alkaline-containing N-groups and CO2 adsorption capacity. Impressively, the pore size distribution arranged from micro-to mesoporous region along with large surface area of 1217 m(2)/g, that is benefit for the adsorption of small acid gas like CO2. Moreover, the adsorption capacity of the optimized ANG-Cs reached 4.89 mmol/g under 298 K and 1 bar, and the predictable adsorption selectivity of pure CO2/N-2 was as high as 43 in the simulated ultra-low emission flue gas. More importantly, when compared with some advanced MOF-based adsorbents, ANG-Cs not only owns similar CO2 adsorption performance, but also keeps higher water resistance, chemical stability and lower cost. Therefore, this promising ANG-Cs with green synthesis for the controllable CO2 adsorption and separation pushes the progress in industry application of ultra-low emission gas.

Automated summary

This study developed ultra-uniform N-doped carbon spheres for efficient CO2 adsorption and high selectivity in simulated ultra-low emission flue gas. The fabrication method and the relationship between porous structures and CO2 adsorption capacity were explored, resulting in an optimized adsorbent with high performance and selectivity. Compared to other adsorbents, this promising ANG-Cs shows potential for controlled CO2 adsorption and separation in industry applications of ultra-low emission gas.