van den Berg AWC, Bromley ST, Flikkema E, Wojdel J, Maschmeyer T, Jansen JC. Molecular-dynamics analysis of the diffusion of molecular hydrogen in all-silica sodalite.
J Chem Phys 2004;
120:10285-9. [PMID:
15268053 DOI:
10.1063/1.1737368]
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Abstract
In order to investigate the technical feasibility of crystalline porous silicates as hydrogen storage materials, the self-diffusion of molecular hydrogen in all-silica sodalite is modeled using large-scale classical molecular-dynamics simulations employing full lattice flexibility. In the temperature range of 700-1200 K, the diffusion coefficient is found to range from 1.610(-10) to 1.810(-9) m(2)/s. The energy barrier for hydrogen diffusion is determined from the simulations allowing the application of transition state theory, which, together with the finding that the pre-exponential factor in the Arrhenius-type equation for the hopping rate is temperature-independent, enables extrapolation of our results to lower temperatures. Estimates based on mass penetration theory calculations indicate a promising hydrogen uptake rate at 573 K.
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