Nitrogen-doped porous carbon spheres derived from d-glucose as highly-efficient CO2 sorbents

Abstract

Carbon spheres were synthesized from D-glucose under hydrothermal conditions. Highly porous N-doped carbon was obtained after the as-synthesized carbon spheres were subjected to urea modification and KOH activation. The resulting sorbent possessed a highly developed narrow microporosity and large amounts of nitrogen-containing groups in the framework, which were confirmed by various characterization techniques such as nitrogen adsorption, X-ray photoelectron diffraction and element analysis, etc. As a result, this sorbent exhibits a high CO₂ adsorption capacity under atmospheric pressure of 4.37 and 6.68 mmol g⁻¹ at 25 °C and 0 °C, respectively. In addition to its high CO₂ adsorption capacity, the sorbent also had a high CO₂/N₂ selectivity of 35, indicating its potential in flue gas separation.