Further Studies of the Interaction of Hydrogen with Graphite Nanofibers

Abstract

Catalytically grown graphite nanofibers (GNF) are molecularly engineered structures that are produced by the interaction of carbon-containing gases with small metal particles at temperatures around 600°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 entirely of nanopores that can accommodate small-sized adsorbate molecules, such as hydrogen, in the most efficient manner. In addition, the nonrigid pore walls can expand to accommodate the gas in a multilayer conformation. GNF exhibit extraordinary behavior toward the sorption and retention of hydrogen at high pressures and abnormally high temperatures. In this paper we discuss some of the critical factors involved in the adsorption of molecular hydrogen and the influence that this process exerts on the structural characteristics of the material. In addition, the deleterious effect of water vapor on the performance of the GNF is highlighted.

Microscopic characterization of metal-carbon-hydrogen composites (metal = Li, Mg)

“…A lot of new carbon materials such as carbon nano tubes (CNTs), activated carbon, and hydrogenated nano-structural graphite (C nano H x ) have been researched to create more efficient hydrogen storage materials. [4][5][6][7][8][9][10][11][12] Among these new carbon materials, we have paid attention to hydrogenated nanostructural graphite. C nano H x is synthesized from graphite by the ball-milling under H 2 gas atmosphere.…”

Hydrogen Adsorption in Carbon Nanostructures: Comparison of Nanotubes, Fibers, and Coals

“…Theoretical calculations: To understand the experimental results we performed density functional theory calculations using Dmol 3 . We used the numerical basis set DND (double numerical with d functions) and the Perdew Wang local correlation density functional.…”

Adsorption Methods of Hydrogen and Methane Storage for the Fuel Cell Application

“…Such switching allows both to solve the environmental problems and to sharply increase the engine efficiency, which in the case of FC is not limited by the Carnot cycle [1]. However, the FC introduction is strongly slowed down by the problems of hydrogen storage or its generation from the suitable sources on board of the vehicle [2][3][4][5][6][7][8][9]. Fueling the automobile with compressed or liquid hydrogen or other gas is additionally complicated by the necessity to create the new infrastructure of fuel dispensing instead of the existing gasoline pump stations.…”

“…In 1998-1999, the Journal of Physical Chemistry has published two works of Rodriguez et al [8,9], which attracted specific attention to the carbon fibers, obtained upon catalyzed decomposition of carbon-containing gases and their mixtures over Ni, Fe, Co and their alloys. The authors of [8] reported the exotic values of Н 2 adsorption upon the exposure of such fibers to Н 2 at 120 atm and 25°C.…”