TY - JOUR
T1 - Understanding the Loading Dependence of Adsorbate Diffusivities in Hierarchical Metal-Organic Frameworks
AU - Chen, Haoyuan
AU - Snurr, Randall Q.
N1 - Funding Information:
The authors gratefully acknowledge DTRA for financial support (Grant HDTRA1-19-1-0007). This research used resources of the National Energy Research Scientific Computing Center (NERSC), a DOE Office of Science User Facility supported by the Office of Science of the U.S. Department of Energy (DE AC02-05CH11231), and the Quest high-performance computing facility at Northwestern University.
Publisher Copyright:
Copyright © 2020 American Chemical Society.
PY - 2020/2/11
Y1 - 2020/2/11
N2 - Using atomistic simulations, we studied the diffusion of n-hexane in a series of isoreticular hierarchical metal-organic frameworks (MOFs) NU-100x. Nonmonotonic diffusivity-loading relationships that depend on the pore sizes were observed, which can be explained by the spatial distribution of adsorbates at different loadings. For one of the MOFs in the series, NU-1000-M, the diffusivity-loading relationship is almost identical to the previously reported results of n-hexane diffusion in the hierarchical self-pillared pentasil (SPP) zeolite. Detailed analysis revealed that the similarity results from their similar micropore and window sizes, which was confirmed by free-energy mapping. The effects of temperature and adsorbate chain length on the diffusion were also studied, which supported our conclusion that the diffusivity in hierarchical nanoporous materials is primarily controlled by the sizes of the micropores and the connecting windows, particularly at relatively low loadings.
AB - Using atomistic simulations, we studied the diffusion of n-hexane in a series of isoreticular hierarchical metal-organic frameworks (MOFs) NU-100x. Nonmonotonic diffusivity-loading relationships that depend on the pore sizes were observed, which can be explained by the spatial distribution of adsorbates at different loadings. For one of the MOFs in the series, NU-1000-M, the diffusivity-loading relationship is almost identical to the previously reported results of n-hexane diffusion in the hierarchical self-pillared pentasil (SPP) zeolite. Detailed analysis revealed that the similarity results from their similar micropore and window sizes, which was confirmed by free-energy mapping. The effects of temperature and adsorbate chain length on the diffusion were also studied, which supported our conclusion that the diffusivity in hierarchical nanoporous materials is primarily controlled by the sizes of the micropores and the connecting windows, particularly at relatively low loadings.
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U2 - 10.1021/acs.langmuir.9b03802
DO - 10.1021/acs.langmuir.9b03802
M3 - Article
C2 - 31957450
AN - SCOPUS:85079249816
VL - 36
SP - 1372
EP - 1378
JO - Langmuir
JF - Langmuir
SN - 0743-7463
IS - 5
ER -