Carbon dioxide adsorption on carbon nanomaterials

Abstract

The adsorption of CO2 on a number of activated carbons, thermal carbon black, and oxide materials at 195 K was studied using static and dynamic techniques. The landing surface areas ω(CO2) ≈ 0.19 nm2 on thermal carbon black and the absolute values of sorption for P/P 0 < 0.4 were determined. The density of adsorbed CO2 in the micropore volume was estimated at ρ(CO2) = 0.91 g/cm3. It was demonstrated that the previously found effect of a weakening of the sorption interaction of nitrogen molecules with thin-walled materials (which manifested itself in an analysis of sorption isotherms by a comparative method) was pronounced to a lesser degree for the sorption of CO2. At the same time, the presence of supermicropores in activated carbon samples resulted in overestimated values of surface areas. A dynamic method was proposed to measure the spectra of CO2 desorption at 195–260 K using a SORBI-MS system for evaluating the binding energy of sorbate molecules with the surface.