Bulletin of the Korean Chemical Society

Korean Chemical Society (대한화학회)
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An X-ray Diffraction Study of Na, Ag-A Reduced by Hydrogen. Ag$_3\;^+$and Ag$_3\;^{2+}$ Clusters

  • Kim, Yang (Chemistry Department, Pusan National University) ;
  • Seff, Karl (Chemistry Department, University of Hawaii)
  • Published : 1984.08.20
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Abstract

The reduction of vacuum-dehydrated $Na_xAg_{12-x}-A, 0 {\le} x {\le} 9.2$, and its reoxidation by O$_2$, have been studied by X-ray powder diffraction. Also, the structure of $Na_6Na_6-A$ treated with hydrogen at room temperature has been studied by single crystal methods in the cubic space group Pm3m at $24{\circ}C (a = 12.221(2) {\AA})$. The diffraction pattern of dehydrated Ag$_{12}$-A reduced by H$_2$ contains only the (111) and (200) reflections of silver metal, indicationg that the zeolite structure has been lost, but the zeolite's diffraction pattern and structural integrity can be fully restored by oxidation with O$_2$ at 100 or 200${\circ}C$. In contrast, the structures of $Na_xAg_{12-x}-A$, x = 4.5 and 9.2, were not destroyed by treatment with hydrogen. Dehydrated Na$_6Ag_6$-A treated with 50 Torr of hydrogen gas at 24${\circ}C$ for 30 minutes has $6\; Na^+\;and\;1.27\;Ag^+$ ions at 6-ring sites. These $Ag^+ ions are associated with 2.54 Ag${\circ}$ atoms to form 1.27 $Ag_3^+$ clusters per unit cell. Also found were 0.7 $Ag_3^{2+}$ clusters per unit cell near the 8-rings. The structure was refined to the final error indices R$_1$ = 0.134 and R$_2$ (weighted) = 0.147, using 168 independent reflections for which $I_0 >3{\sigma}(I_0)$.

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References

  1. Catal. Rev. v.10 W. M. H. Sachtler
  2. J. Catal. v.32 Y-Y. Huang
  3. Metal Microstructure in Zeolites H. K. Beyer;P. A. Jacobs;P. A. Jacobs(et al.)(ed.)
  4. 184th ACS Meeting, division of Inorganic Chmistry, Abs. 71 G. A. Ozin;F. Huges;S. Martar;D. Micintosh
  5. J. Phys. Chem. v.82 Y. Kim;K. Seff
  6. Zeolites Y. Kim;K. Seff
  7. ACS Symposiun Series v.135 Y. Kim;V. Subramanian;R. L. Firor;K. Seff
  8. J. Cryst. Growth v.8 J. F. Charnell
  9. J. Phys. Chem. v.76 K. Seff
  10. J. Phys. Chem. v.76 R. Y. Yanagida;K. Seff
  11. Acta Crystallogr. v.10 S. W. Peterson;H. A. Levy
  12. J. Aerm. Chem. Soc. v.100 Y. Kim;K. Seff
  13. Lp data reduction program T. Ottersen
  14. UCLA LS4, American Crystallographic Association Program Library (old) No. 317 full-matrix least-squares P.K. Gantzel;R.A. Sparks;K.N. Trueblood
  15. Ames Laboratory Fast Fourier Fourier program C. R. Hubbard;C. O. Quicksall;R. A. Jacobson
  16. Ortep, Report No. ORNL-3794 C. K. Johnson
  17. J. Phys. Chem. v.82 Y. Kim;K. Seff
  18. J. Amer. Chem. Soc. v.100 Y. Kim;K. Seff
  19. J. Phys. Chem. v.81 V. Subramanian;K. Seff
  20. Acta. Crystallogr. v.2 D. W. J. Cruickshank
  21. International Tables for X-ray Crystallography v.IV
  22. International Tables for X-ray Crystallography v.IV
  23. J. Amer. Chem. Soc. v.99 Y. Kim;K. Seff
  24. Handbook of Chemistry and Physics(63rd ed.)
  25. J. Phys. Chem. v.82 Y. Kim;K. Seff
  26. Inorganic Chemistry J. E. Huheey
  27. J. Phys. Chem. v.77 R. Y. Yanagida;A. A. Amaro;K. Seff
  28. Acc. Chem. Res. v.9 K. Seff
  29. J. Amer. Chem. Soc. v.99 Y. Kim;J. W. Gilje;K. Seff
  30. J. Chem. Soc. Chem. Comm. P.A. Jacobs;J. B. Uytterhoeven;H.K. Beyer
  31. J. Chem. Soc. Faraday Tran. I v.72 H. K. Beyer;P. A. Jacobs;J. B. Uytterhoeven
  32. Bull. Chem. Soc. Japan v.45 K. Tsutsumi;H. Takahashi