%0 Conference Paper
%F Oral 
%T High density hydrogen films adsorbed in engineered carbon nanospaces
%+ Department of Physics and Astronomy [Columbia] (Mizzou Physics)
%+ Laboratoire Charles Coulomb (L2C)
%+ Matériaux divisés, interfaces, réactivité, électrochimie (MADIREL)
%A Pfeifer, P
%A Gillespie, A.
%A Dohnke, E.
%A Firlej, Lucyna
%A Kuchta, B
%F Invité
%< avec comité de lecture
%Z L2C:17-338
%B European Congress and Exhibition on Advanced materials and Processes EUROMAT 2017
%C Thessalonique, Greece
%8 2017-09-17
%D 2017
%Z Physics [physics]/Physics [physics]/Computational Physics [physics.comp-ph]
%Z Physics [physics]/Condensed Matter [cond-mat]/Materials Science [cond-mat.mtrl-sci]Conference papers
%X The search for sustainable automotive fuels has driven numerous studies of sorption-based hydrogen storage for hydrogen fuel cell vehicles. Storage by adsorption is fully reversible, achieves fast fill/discharge demands by simple pressurization/depressurization, and operates at much lower pressure than compressed hydrogen and at much less demanding temperatures than liquid hydrogen. In support of the DOE 2020 storage capacity target of 40 g hydrogen/L system, we have investigated the density of the adsorbed hydrogen films in a variety of porous carbons synthesized at the University of Missouri. The investigation decomposes storage into a high-density adsorbed film and low-density non-adsorbed gas and determines the fraction of pore volume occupied by the two phases.We find exceptionally dense H2 films at liquid nitrogen temperature, 77 K. Saturated film densities are 100-120 g/L across all samples at pressures as low as 35-70 bar. This is 1.4-1.7 times the density of liquid hydrogen at its normal boiling point, 71 g/L (20 K). Experimental film thicknesses are 0.30-0.32 nm, and fractions of total pore volume filled with high-density film are 0.25-0.53. Thus high storage capacities, well in excess of the DOE target and even in excess of liquid hydrogen, can be achieved at 77 K in appropriately engineered nanoporous carbons.The dense films occur at a temperature more than twice the liquid-gas critical temperature of hydrogen, 33 K, above which no bulk liquid exists at any pressure. The high-density film above 33 K does not contradict the non-existence of bulk liquid: the film is not a bulk, 3D phase, but a monomolecular 2D phase. Monte Carlo simulations confirm the observed high density and small film thickness. The film density and volume remain constant up to gas densities ~80% of the film density. A discussion in terms of competing forces acting on adsorbed molecules will be given.
%G English
%L hal-01938851
%U https://hal.science/hal-01938851
%~ CNRS
%~ UNIV-AMU
%~ L2C
%~ INC-CNRS
%~ MADIREL
%~ MIPS
%~ UNIV-MONTPELLIER
%~ TEST-HALCNRS
%~ UM-2015-2021
%~ TEST2-HALCNRS