Journal of CO2 Utilization, 2019, vol 31pp. 124-134
Adsorption of CO2 on three-dimensionally ordered micromesoporous carbon with a spherical pore structure has been studied using gravimetric and manometric analyses. Adsorptive properties were compared with activated carbon and nanostructured carbon materials such as carbon nanotubes, zeolitic-imidazolate framework-derived carbon, carbon nanohorns and ordered mesoporous carbon materials. The regular spherical pores of 1415?nm diameter with a large pore volume of 3.4 cm3?g?1 provided a very high CO2 adsorption capacity exceeding the compared carbon materials at high gas pressures (?4?MPa and room temperature). A strong increase in the isosteric heat of CO2 adsorption with increasing surface coverage indicates that high pressure adsorption was predominantly controlled by strong quadrupole moment interactions between CO2 molecules and less intensive interactions of CO2 with the mesoporous surface. Micropores in the walls of the main spherical mesopores, with a pore volume of 0.17?cm3?g?1, provided good CO2 adsorption properties at atmospheric pressure, characterized by rectilinear isotherms and a predominant surface coverage mechanism. Analysis of the strength of CO2 interaction with the carbon adsorbent and a kinetic study of CO2 adsorption revealed excellent CO2 adsorption-desorption reversibility.