Insitu analytical investigation of redox behavior of Cu-ZSM-5 catalysts

Abstract

The utilization of insitu DRIFT spectroscopy combined with advanced thermoanalytical techniques (temperature programmed decomposition, TPDE; temperature programmed oxidative decomposition, TPOD) allows the characterization of redox behavior of copper ions inside ZSM-5 zeolites. The oxidation of carbonaceous impurities inside the solid matrix to CO and CO₂ is demonstrated to be responsible for Cu(II)→Cu(I) reduction, since the formation of other oxidation products, namely O₂, H₂O₂ or O₂^- ions, was not detected by mass spectrometry and DRIFT. The unusual kinetics of CO evolution in thermoanalytical experiments was attributed to the formation of a relatively stable Cu⁺···CO adduct characterized by a typical IR band at 2157 cm^-1, which acts as a specific active site of a chromatographic adsorbent material.

References

1. M. Iwamoto, H. Furukawa, Y. Mine, F. Uemura, S. Mikuriya and S. Kagawa, J. Chem. Soc., Chem. Commun., 1986, 1272; M. Iwamoto, H. Yahiro, N. Mizuno, W.-X. Zhang, Y. Mine, H. Furukawa and S. Kagawa, J. Phys. Chem., 1992, 96, 9360.
2. W. Held and A. Koenig, Ger. Offen, DE 3642018 (1987) to Volkswagen A. G; W. Held, A. Koenig, T. Richter and L. Puppe, SAE Paper 900496, 1990.
3. G. Centi and S. Perathoner, Appl. Catal. A, 1995, 132, 179.
4. M. Shelef, Chem. Rev., 1995, 95, 209.
5. G. Moretti, Catal. Lett., 1994, 28, 143.
6. D. C. Sayle, C. R. A. Catlow, J. D. Gale, M. A. Perrin and P. Nortier, J. Phys. Chem. A, 1997, 101, 3331.
7. T. Beutel, J. Sarkany, G. D. Lei, J. Y. Yan and W. M. H. Sachtler, J. Phys. Chem., 1996, 100, 845.
8. R. Burch and P. J. Millington, Appl. Catal. B, 1993, 2, 101.
9. S. C. Larsen, A. Ajol, A. T. Bell and J. A. Reimer, J. Phys. Chem., 1994, 98, 11533.
10. B. L. Trout, A. K. Chakraborty and A. T. Bell, J. Phys. Chem., 1996, 100, 4173.
11. S. Hu, J. A. Reiner and A. T. Bell, J. Phys. Chem. B, 1997, 101, 1869.
12. J. Sarkany, J. Mol. Struct., 1997, 410–411, 137; ibid., 1997, 410–411, 95.
13. M. J. Remy and G. Poncelet, J. Phys. Chem., 1995, 99, 773.
14. G. Bellussi, C. Perego, A. Carati, S. Peratello, E. Previde Massara and G. Perego, Stud. Surf. Sci. Catal., 1994, 84, 85.
15. C. Dossi, A. Fusi, G. Moretti, S. Recchia and R. Psaro, Appl. Catal. A, 1999, 4754, 1.
16. C. Dossi, P. Losi and S. Calmotti, Ann. Chim. (Rome), 1993, 83, 233.
17. C. Dossi, A. Fusi, R. Psaro and G. M. Zanderighi, Appl. Catal., 1989, 46, 145.
18. C. Dossi, A. Fusi, R. Psaro and D. Roberto, Thermochim. Acta, 1991, 182, 273.
19. C. Dossi, A. Fusi and R. Psaro, Thermochim. Acta, 1994, 236, 165.
20. C. Dossi, A. Fusi, G. Molteni, S. Recchia and R. Psaro, Analyst, 1997, 122, 279.
21. C. Dossi and A. Fusi, Anal. Chim. Acta, 1989, 217, 197.
22. N. S. Harris, Modern Vacuum Practice, McGraw-Hill, London, 1989, p. 67.
23. J. A. R. Van Veen, P. C. Jong-Versloot, G. M. M. Van Kessel and F. J. Feels, Thermochim. Acta, 1989, 152, 359.
24. G. Moretti, C. Dossi, A. Fusi, S. Recchia and R. Psaro, Appl. Catal. B, 1999, 20, 67.
25. N. Masciocchi, E. Corradi, A. Sironi, G. Moretti, G. Minelli and P. Porta, J. Solid State Chem., 1997, 131, 252.
26. W. K. Hall, X. Feng, J. Dumesic and R. Watwe, Catal. Lett., 1998, 52, 13.
27. G. Spoto, A. Zecchina, S. Bordiga, G. Ricchiardi, G. Martra, G. Leofanti and G. Petrini, Appl. Catal. B, 1994, 3, 151.