A comparative study of H2, CH4 and CO2 adsorption on functionalized multi-walled carbon nanotubes

Adsorption of simple gas molecules on carbon nanotubes has been studied extensively for potential applications as gas storage. Dillon et al. [1] were the first who published the experimental hydrogen adsorption in non-purified SWNTs, thereafter many research groups started to carry out hydrogen storage experiments, and reported some noticeable results in nanostructure materials [2]. In addition, a large number of experimental studies of methane adsorption have been reported in nanostructured materials [3]. These researches tried to investigate the mechanism of adsorption of a specific gas on carbon nanotubes, although a comparative study for the simple gases on these materials is less reported. The present work is focused on the comparative study of H2, CH4 and CO2 adsorption on a kind of functionalized MWNTs, OH-MWNTs, by the volumetric measurements at different moderate temperatures and pressures