Study of hydrogen physisorption on nanoporous carbon materials of different origin

Hydrogen adsorption capabilities of different nanoporous carbon, i.e. amorphous carbons obtained by chemical activation(withKOH) of a sucrose-derived char previously ground by ball millingandcarbonreplicas ofNH4-Yandmesocellular silicafoam(MSU-F) inorganic templates, were measured and correlated to their porous properties. The porous texture of the prepared carbon materials was studied by means of N2 and CO2 adsorption isotherms measured at 196 C and 0 C, respectively. Comparison with nanoporous carbons obtained without pregrinding the sucrose-derived char [12] shows that the ball milling procedure favours the formation of highly microporous carbon materials even at low KOH loadings, having a beneficial effect of the interaction between the char particles and the activating agent. Hydrogen adsorption isotherms at 196 C were measured in the 0.0e1.1 MPa pressure range, and amaximumhydrogen adsorption capacity of 3.4 wt.%was obtained for theamorphous carbon prepared by activation at 900 C with a KOH/char weight ratio of 2. Finally, a linear dependence was found between the maximumhydrogen uptake at 1.1 MPa and the samples microporous volume, confirming previous results obtained at 196 C and sub-atmospheric pressure [12].