Note: Molecular diffusivity in a small pore zeolite measured by a variable pressure (piezometric) uptake method (original) (raw)

Abstract

The use of numerical analysis to solve the diffusion equation in the uptake method allowed the measurement of molecular diffusivity in a zeolite with a variable pressure around it. The diffusivity was obtained from the data in the measurement of the adsorption isotherm, which means that the diffusivity measurement now needs neither a special instrument nor procedure. The diffusivities of all the gases are readily available from the measurement of their adsorption isotherms and these data include how the diffusivity changes versus adsorbed concentration. The modeling introduced can also be used for a zeolite with a surface barrier.

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References (19)

  1. M. R. Bonilla, T. Titze, F. Schmidt, D. Mehlhorn, C. Chmelik, R. Valiullin, S. K. Bhatia, S. Kaskel, R. Ryoo, and J. Kärger, Materials 6, 2662 (2013);
  2. M. R. Bonilla, R. Valiullin, J. Kärger, and S. K. Bhatia, J. Phys. Chem. C 118, 14355 (2014);
  3. J. Kärger, Microporous Mesoporous Mater. 189, 126 (2014);
  4. ChemPhysChem 16, 24 (2015).
  5. R. Kolvenbach, L. F. Gonzalez Peña, A. Jentys, and J. A. Lercher, J. Phys. Chem. C 118, 8424 (2014).
  6. J. Kärger, D. M. Ruthven, and D. N. Theodorou, in Diffusion in Nanoporous Materials (Wiley-VCH Verlag, Weinheim, 2012), Chap. 13.
  7. M. Bülow, P. Struve, G. Finger, C. Redszus, K. Ehrhardt, W. Schirmer, and J. Kärger, J. Chem. Soc., Faraday Trans. 1 76, 597 (1980);
  8. M. Bülow and A. Micke, Adsorption 1, 29 (1995).
  9. Y. X. Li, M. Y. Zhang, D. Z. Wang, F. Wei, and Y. Wang, J. Catal. 311, 281 (2014).
  10. Y. Kobayashi, F. Wang, Q. X. Li, and D. Z. Wang, Rev. Sci. Instrum. 85, 34101 (2014).
  11. J. Crank, The Mathematics of Diffusion, 2nd ed. (Oxford University Press, 1975), p. 5.
  12. W. H. Press, S. A. Teukolsky, W. T. Vetterling, and B. P. Flannery, Numerical Recipes, 3rd ed. (Cambridge University Press, Cambridge, UK, 2007), p. 1046.
  13. J. H. Guo, Y. X. Li, Y. H. Huang, and D. Z. Wang, J. Nanosci. Nanotechnol. 14, 6858 (2014).
  14. D. H. Olson, M. A. Camblor, L. A. Villaescusa, and G. H. Kuehl, Microp- orous Mesoporous Mater. 67, 27 (2004).
  15. S. C. Reyes, V. K. Krishnan, G. J. DeMartin, J. H. Sinfelt, K. G. Strohmaier, and J. G. Santiesteban, U.S. patent 6,730,142 (4 May 2004).
  16. K. Agarwal, M. John, S. Pai, B. L. Newalkar, R. Bhargava, and N. V. Choudary, Microporous Mesoporous Mater. 132, 311 (2010).
  17. D. M. Ruthven and S. C. Reyes, Microporous Mesoporous Mater. 104, 59 (2007).
  18. R. Schumacher, K. Ehrhardt, and H. G. Karge, Langmuir 15, 3965 (1999);
  19. S. Brandani, Adsorption 4, 17 (1998).