Synthesis of nitrogen-doped carbon with three-dimensional mesostructures for CO2 capture

The objective of this research was to develop a new CO2 sorbent, three-dimensional nitrogen-doped mesoporous carbon (KIT-6-CN). KIT-6-CN was synthesized by nano-replication using carbon tetrachloride and ethylenediamine as precursors, and KIT-6 with cubic Ia3d symmetry as a hard template. The new CO2 sorbent has a relatively high BET surface area of 587 m2/g, a high pore volume of 0.91 cm3/g, and the mesostructures with pore diameters centered at 1.7 and 6.3 nm. The transmission electron microscopy of the KIT-6-CN shows that after removal of silica by NaOH, KIT-6-CN possesses three-dimensional mesoporous structure. CO2 adsorption–desorption isotherms indicate that this nitrogen-doped material has relatively high CO2 capture capacities of 2.11 mmol/g at 25 °C and 3.09 mmol/g at 0 °C, which are superior to those of the pure carbon material (KIT-6-C) with analogous mesostructures. Cyclic CO2 sorption–desorption tests demonstrated the stability of the sorbent. Thus, the new sorbent can potentially be a good candidate for CO2 capture.