Assessment of Ultramicroporosity on Carbon Molecular Sieves by Water Adsorption

This work is focused on the application of water adsorption to the characterisation of the narrow microporosity (ultramicroporosity) in carbon molecular sieves (CMS). In addition, the mechanism of water adsorption in carbonaceous solids was analysed. Despite the presence of surface groups in these materials, they exhibited low adsorption at low relative pressures (P/P 0 < 0.2), indicating the significant role of micropore size in the commencement of water adsorption. Interestingly, it was observed that water adsorbed on samples that did not exhibit CO 2 adsorption.