Adsorption of CO2 and H2 on nitrogen-doped porous carbon from ionic liquid precursor

Abstract

Nitrogen-doped mesoporous carbon material was prepared via a simple one-step thermolysis method via the carbonization of ionic liquid, 1-cyanomethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide([MCNIm]+[Nf2T]−). The nanostructure of the resultant carbon material was characterized by X-ray diffraction(XRD) and transmission electron microscopy(TEM) and the types of N-containing groups of the carbon material were investigated by X-ray photoelectron spectroscopy(XPS). The N-content of the carbon material is 18.6%(mass fraction) based on the elemental analysis. The produced mesoporous carbon material was further used as the solid sorbent for H2 and CO2. The hydrogen uptake capacity and H2 isosteric heat of the carbon material were discussed. Furthermore, the nitrogen-containing carbon material as good sorbent shows relatively high adsorption and separation ability for CO2 from CH4, for which the heat of CO2 adsorption(Q st) is 31.8 kJ/mol. The mesoporous structure and nitrogen functionality make the carbon material with high adsorption capacity and selectivity for CO2 and ability to store H2, indicating that this kind of nitrogen-doped carbon material originated from ionic liquids is a promising sorbent material for high-performance separation and adsorption.