Vol. 21 No. 3 (2018) Cover Image
Vol. 21 No. 3 (2018)

Published: September 30, 2018

Pages: 428-435

Articles

Fourier Transformation Infrared Spectroscopic Studies of Acidity of NaH-13 X Zeolites

Shatha Abd-Alhameed Al. Sofy 1
1 Institute of Technology, Middle Technical University, Baghdad, IRAQ
History
  • Received: June 14, 2018
  • Available Online: September 1, 2018
DOI

https://doi.org/10.29194/NJES.21030428

Abstract

Fourier transformation Infrared spectroscopy (FTIR) has been used to characterize and measure the concentration of acid sites (Si-OH-Al groups) in NaH-13 X Zeolites. Ion exchange was followed by dealumination to get (28, 40, 65, 85.8 and 97.5 Wt. %) of NaH-13 X Zeolites samples. The conclusion of homogeneity of OH groups was obtained by analysis of Fourier transformation infrared spectroscopy absorption bands of OH groups after adsorption and desorption of Ammonia. It found that there were different acid sites on a broader absorption (3,800-3,000 cm-1) corresponds to hydroxyl groups of the less acidic Brønsted acid sites approximately at 3464cm-1 and the more acidic at 3441cm-1 and Lewis acid sites was found at 1636 cm-1 which is few and weak acid sites . It can be conclusion that concentrations of OH groups increased with increasing the exchange degree and delamination. The concentration of acid sites in samples were calculated from stretching frequencies and extinction coefficients of OH bands, also the frequency shift  ??OH = 23 cm-1 which was due to the hydrogen bonding of OH groups with ammonia in 97.5 % NaH-13 X Zeolites. Knowing the acidity of catalyst is important for the reactions which required acidic surface.

Keywords

References

  1. C. Otero Arean et. al, the combined use of acetonitrile and adamantane –carbonitrile as IR spectroscopic probes to discriminate between external and internal surfaces of medium pore zeolites, Journal Microporous and Mesoporous Materials , 34(2000) 55-60.
  2. Nikolay Cherkasov, Tanya Vazhnova , Dmitry B. Lukyanov, Quantitative infra-red studies of Brønsted acid sites in zeolites : Case study of the zeolite mordenite, J. Vibrational spectroscopy,83(2016)170-179.
  3. H. A. Benesi and B. H. C. Winquist: Surface Acidity of Solid Catalysts, J. Advances in catalysis , 27 (1978) 97.
  4. M. Maache, A. Janin, J.C. Lavalley, and E. Benazzi, FT infrared study of Brønsted acidity of H-mordenites : Heterogeneity and effect of delamination, J. Zeolites 15; 507-516, (1995).
  5. J. Datka and B. Gil, Heterogeneity of OH Groups in Faujasites studied by IR Spectroscopy, Journal of Catalysis 145,372-376 (1994).
  6. J. Datka , B. Gil ,Teresa, K.G. Domagala, Homogeneous OH groups in dealuminated HY zeolite studied by IR spectroscopy, J. Microporous and Mesoporous Materials 47 (2001) 61-66.
  7. J. Datka , B. Gil, Heterogeneity of OH groups in HZSM-5 zeolites, IR studies of ammonia adsorption and desorption, Journal of Molecular Structure, 596(2001) 41-45.
  8. J. Datka , B. Gil and A. Kubacka ,Acid properties of NaH - mordenites : Infrared spectroscopic studies of ammonia sorption , J. Zeolites 15;501-506 ,(1995).
  9. Masato Takeuchi, Tatsuya Tsukamoto, Atsushi Kondo and Masaya Matsuoka, Investigation of NH3 and NH4+ adsorbed on ZSM-5 zeolites by near and middle infrared spectroscopy, Catalysis Science and Technology (2015),5, 4587-4593.
  10. O. Cairon , K. Thomas, A. Chambellan ,T. Chevreau, Acid – catalysed benzene hydroconversion using various zeolites : Brønsted acidity ,hydrogenation and side – reactions, J. Applied Catalysis A :General 238 (2003) 167-183.
  11. M. Guisnet, P. Ayrault, J. Datka, Acid properties of mazzite zeolites studied by IR spectroscopy, J. Microporous and Mesoporous Materials 20(1997)283-291 .
  12. Shashikant A. Kadam, Mariya V. Shamzhy, IR Operando Study of Ethanol Dehydration over MFI Zeolite, Catalysis Today, Accepted Manuscript, 9-9-2017.
  13. Paola Lanzafame, Katia Barbera, Georgia, Comparison of H+ and NH4+ forms of zeolites as acid catalysts for HMF etherification, Catalysis Today, Accepted Manuscript, 2-8-2017.
  14. Ying Li, Qi, Sun, Shouying Huang, Zaizhe Cheng, Kai Cai, Jing Lv, Xinbin, Dimethyl ether carbonylation over pyridine – modified MOR : Enhanced stability influence by acidity, Catalysis Today, volume 311, 2018 , Pages81-88.
  15. K. Gora-Marek , J. Datka ,IR studies of OH groups in mesoporous aluminosilicates, J. Applied Catalysis A :General 302 (2006) 104-109.
  16. Meloni, S. Laforge, D. Martin, M. Guisnet, E. Rombi, Solinas, Acidic and catalytic properties of H-MCM-22 zeolites, characterization of the acidity by pyridine adsorption, J. of Applied Catalysis A: General 215 (2001) 55-66.
  17. J. Datka, B. Gill, and Kubacka, Heterogeneity of OH groups in NaH- mordenites: Effect of Na/H exchange degree, J. Zeolites 18: 245-249, 1997.
  18. J. Datka , B. Gil, P. Baran, IR Study of heterogeneity of OH groups in zeolite HY-splitting of OH and OD bands, Journal of Molecular Structure, 645 (2003) 45-49.