Hydrogen adsorption on a single-walled carbon nanotube material:: a comparative study of three different adsorption techniques

Hydrogen adsorption measurements on mixed carbon material containing single-walled carbon nanotubes (SWNTs) obtained by the electric-arc method were carried out by three different techniques: a volumetric system, a gravimetric system and an electrochemical method. The found H-2 gas adsorption capacity (volumetric and gravimetric) is very low, around 0.01 wt% at room temperature and pressure, increasing to 0.1 wt% at 20 bar. Electrochemical measurements show a slightly higher capacity (0.1-0.3 wt%) than volumetric and gravimetric data. The results obtained by the three different techniques are compatible within each other and they are also in good agreement with other previously reported data from different researchers.