To characterise accurately the surface of porous carbons a combination of molecular models and experimental techniques is used. The nature of graphitic and activated carbon surfaces and their adsorption characteristics are investigated by scanning electron microscopy, x-ray diffraction and experimental and theoretical adsorption isotherms. The nature of the pore spaces filled by different gases at different temperatures are explored using molecular models at the nanoscale and structural models (slit-pore) on the mesoscale. Density Functional Theory which is based on statistical mechanics was used to model adsorption isotherms for various gases at 77K and 293K in idealised porous systems.
Porous carbons were characterised by applying a numerical method to determine the distribution of pores of varying size. The reliability of the pore size distribution, widely determined from nitrogen adsorption isotherms at 77K, has been improved by considering other gases such as argon, carbon-dioxide and methane and higher temperatures. Finally, the pore size distribution of a typical microporous carbon was used to predict its adsorption selectivity properties.