Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
73806 | Microporous and Mesoporous Materials | 2013 | 7 Pages |
Diffusion of pentane isomers in zeolites NaX has been investigated using pulsed field gradient nuclear magnetic resonance (PFG-NMR) and molecular dynamics (MD) techniques respectively. Temperature and concentration dependence of diffusivities have been studied. The diffusivities obtained from NMR are roughly an order of magnitude smaller than those obtained from MD. The dependence of diffusivity on loading at high temperatures exhibits a type I behavior according to the classification of Karger and Pfeifer [1]. NMR diffusivities of the isomers exhibit the order D(n-pentane)>D(isopentane)>D(neopentane)D(n-pentane)>D(isopentane)>D(neopentane). The results from MD suggest that the diffusivities of the isomers follow the order D(n-pentane)
Graphical abstractPentane isomers in zeolite NaY. Two alpha cages connected through a 12 membered window is shown in the figure. The blue molecules are the pentane isomers.Figure optionsDownload full-size imageDownload as PowerPoint slideHighlights► NMR and MD study of pentane isomers in faujasite. ► Diffusivities and activation energies reported. ► Differences in the results attributed to differences in time scale of observation.