RESEARCH ARTICLE

 

Effects of copper exchange levels on complexation of ammonia in Cu (II)-exchanged X zeolite

 

 

Chrispin O. Kowenje^{I, *}; David C. Doetschman^II; Jürgen Schulte^II; Charles W. Kanyi^II; Jared DeCoste^II; Szu-Wei Yang^II; Barry R. Jones^II

^IDepartment of Chemistry, Maseno University, Box 333 - 40105, Maseno, Kenya
^IIDepartment of Chemistry, Binghamton University, Vestal Parkways East, Binghamton, NY 13902-6000, USA

 

 

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ABSTRACT

Copper (Il)-exchanged faujasite-X zeolites at various loadings of copper per unit cell of zeolites were prepared and then exposed to ammonia. The copper ammine complexes of the various copper levels per unit cell were characterized and analyzed by a combination of diffuse reflectance, X-ray powder diffraction, FT-infrared spectroscopy, electron paramagnetic resonance and nuclear magnetic resonance spectroscopic methods. At low copper exchange levels (<5 copper atoms per unit cell), the major complex is [Cu(O_zeo)₂(NH₃)₂]²⁺ and it is strongly bound to the zeolite framework walls at single four ring sites (site III). Above five copper atoms per unit cell, the major complex becomes [Cu(NH₃)₄]²⁺ and it is least interacting with the zeolite framework walls. The [Cu(NH₃)₄]²⁺ complex which was formed at higher copper levels per unit cell was most favoured by the presence of maximal amount of ammonia.

Keywords: Cation exchange, catalysis, copper, complexation, copper ammines

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Acknowledgements

The authors are grateful for the financial support of the SAIC Corporation, Institute for Hazardous Materials Management. We are equally thankful to Dr Daniel Brennan of State University of New York at Broome Community College for help with the X-ray measurements.

 

References

1 F.-S. Xiao,W. Zhang, M. Jia, Y. Yu, C. Fang, G. Tu, S. Zheng, S. Qiu and R. Xu, Catal. Today, 1999, 50, 117–123.         [ Links ]

2 S. Miao, Y. Wang, D. Ma, Q. Zhu, S. Zhou, L. Su, D. Tan and X. Bao, J. Phys. Chem. B, 2004, 108, 17866–17871.         [ Links ]

3 A.J. Hernandez-Maldonado and R.T. Yang, J. Am. Chem. Soc., 2004, 126, 992–993.         [ Links ]

4 Y.-Y. Huang and E.F. Vansant, J. Phys. Chem., 1973, 77, 663–667.         [ Links ]

5 J. Hunger, J. Boehm, H. Boehlig and B. Hunger, Stud. Surf. Sci. Catal., 2008, 174A, 745–750.         [ Links ]

6 E. Jaramillo, C.P. Grey and S.M. Auerbach, J. Phys. Chem. B, 2001, 105, 12319–12329.         [ Links ]

7 S.-B. Liu, T.-S. Lin, T.-C. Yang, T.-H. Chen, E.-C. Hong and R. Ryoo, J. Phys. Chem., 1995, 99, 8277–8282.         [ Links ]

8 J. Dwyer, R.V. Parish and N. P. Evmerides, Inorg. Chim. Acta, 1983, 75, 229–234.         [ Links ]

9 N.J. Turro, X. Lei, W. Li, Z. Liu and M.F. Ottaviani, J. Am. Chem. Soc., 2000, 122, 12571–12581.         [ Links ]

10 N. Ohata, Y. Ito, D. Gomibuchi, H. Kitamura, Y. Furahashi, T. Ozawa and H. Masuda, Adv. Mat. Res., 2006, 281, 11–12,         [ Links ]

11 C.O. Kowenje, B.R. Jones, D.C. Doetschman, S.-W. Yang and C.W. Kanyi, Chem. Phys., 2006, 333, 401–409.         [ Links ]

12 M. Narayana, S. Contarini and L. Kevan, J. Catal., 1985, 94, 370–375.         [ Links ]

13 B.O. Hincapie, L.J. Garces, S. Gomez, R. Ghosh and S.L. Suib, Catal. Today, 2005, 110, 323–329.         [ Links ]

14 I.E. Maxwell, J.J. DeBoer and R.S. Downing, J. Catal., 1980, 61, 493–502.         [ Links ]

15 J.-S. Yu, J. Kim and L. Kevan, Micro. Mesoporous Mater., 2000, 40, 135–147.         [ Links ]

16 J. Piesach and W.E. Blumberg, E. Arch. Biochem. Biophys., 1974, 165, 691–708.         [ Links ]

17 P. Carl and S. Larsen, J. Catal., 1999, 182, 208–218.         [ Links ]

18 S. Kieger, G. Delahay, B. Coq and B. Neveu, J. Catal., 1999, 183, 267–280.         [ Links ]

19 U.D. Joshi, P.N. Joshi, S.S. Tamhankar, V.V. Joshi and V.P. Shiralkar, J. Phys. Chem. B, 2001, 105, 10637–10647.         [ Links ]

20 T.M. Salama, A.H.Ahmedand Z.M. El-Bahy, Micro. Mesoporous Mater., 2006, 89, 251–259.         [ Links ]

21 J.A. Van Bokhoven, A.L. Roest, D.C. Koningsberger, J.T. Miller, G.H. Nachtegaal and A.P.M. Kentgens, J. Phys. Chem. B, 2000, 104, 6743–6754.         [ Links ]

 

 

Received 14 January 2009
Revised 17 October 2009
Accepted 23 November 2009

 

 

* To whom correspondence should be addressed. E-mail: ckowenje@maseno.ac.ke