Further studies of the interaction of hydrogen with graphite nanofibers

Catalytically grown graphite nanofibers (GNF) are molecularly engineered st ructures that are produced by the interaction of carbon-containing gases wi th small metal particles at temperatures around 600 degrees C. The fibrous solids consist of minuscule graphene sheets stacked at various angles with respect to the fiber axis. This arrangement generates a material possessing unique chemical properties because unlike conventional graphite crystals, only edges are exposed. Such a conformation produces a material composed en tirely of nanopores that can accommodate small-sized adsorbate molecules, s uch as hydrogen, in the most efficient manner. In addition, the nonrigid po re walls can expand to accommodate the gas in a multilayer conformation. GN F exhibit extraordinary behavior toward the sorption and retention of hydro gen at high pressures and abnormally high temperatures. In this paper we di scuss some of the critical factors involved in the adsorption of molecular hydrogen and the influence that this process exerts on the structural chara cteristics of the material. In addition, the deleterious effect of water va por on the performance of the GNF is highlighted.