Print Email Facebook Twitter Effect of cation distribution on self-diffusion of molecular hydrogen in Na3Al3Si3O12 sodalite:?A molecular dynamics study Title Effect of cation distribution on self-diffusion of molecular hydrogen in Na3Al3Si3O12 sodalite:?A molecular dynamics study Author Van den berg, A.W.C. Bromley, S.T. Flikkema, E. Jansen, J.C. Faculty Applied Sciences Department DelftChemTech Date 2004-11-22 Abstract The diffusion of hydrogen in sodium aluminum sodalite (NaAlSi-SOD) is modeled using classical molecular dynamics, allowing for full flexibility of the host framework, in the temperature range 800–1200 K. From these simulations, the self-diffusion coefficient is determined as a function of temperature and the hydrogen uptake at low equilibrium hydrogen concentration is estimated at 573 K. The influence of the cation distribution over the framework on the hydrogen self-diffusion is investigated by comparing results employing a low energy fully ordered cation distribution with those obtained using a less ordered distribution. The cation distribution is found to have a surprisingly large influence on the diffusion, which appears to be due to the difference in framework flexibility for different cation distributions, the occurrence of correlated hopping in case of the ordered distribution, and the different nature of the diffusion processes in both systems. Compared to our previously reported calculations on all silica sodalite (all-Si-SOD), the hydrogen diffusion coefficient of sodium aluminum sodalite is higher in the case of the ordered distribution and lower in case of the disordered distribution. The hydrogen uptake rates of all-Si-SOD and NaSiAl-SOD are comparable at high temperatures ( ? 1000?K) and lower for all-Si-SOD at lower temperatures ( ? 400?K). Subject self-diffusionsodium compoundsaluminium compoundsmolecular dynamics methodpositive ions To reference this document use: http://resolver.tudelft.nl/uuid:5ce8485e-a9b7-480b-9288-b28a91385c1b DOI https://doi.org/10.1063/1.1808119 Publisher American Institute of Physics ISSN 0021-9606 Source http://link.aip.org/link/JCPSA6/v121/i20/p10209/s1 Source Journal of Chemical Physics, 121 (20), 2004 Part of collection Institutional Repository Document type journal article Rights (c) 2004 The Author(s); American Institute of Physics Files PDF vandenBerg_2004.pdf 403.75 KB Close viewer /islandora/object/uuid:5ce8485e-a9b7-480b-9288-b28a91385c1b/datastream/OBJ/view