Luis F. D´Elia,* R. Ortíz
Universidad de los Andes, Facultad de Ciencias, Departamento de Química, Laboratorio de Electroquímica, Mérida 5101, Venezuela
Abstract
The electro-oxidation of toluene in 0.1 M But4NPF6 + CH3CN solutions on glassy carbon electrodes was studied using electrochemical and spectroelectrochemical techniques. Toluene electro-oxidation yields an electrochemical inactive film on the electrode surface. In situ Fourier Transformed Infrared (FTIR) studies suggest the formation of a polymeric film, as the main product, on the surface. Depending on the experimental time scale toluene transformation is a complex reaction that could involve adsorption processes, pure charge transfer reaction and couple chemical reactions. Additions of small quantities of water to the electrolyte cause a cathodic displacement of the oxidation peak potential; in other words, the electro-oxidation reaction is favoured.
Keywords: electrochemical oxidation, toluene, organic medium, glassy carbon, in situ FTIR.
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References
1. K. Rajeshwar, J.G. Ibañez, Environmental Electrochemistry: Fundamentals and Applications Abatement, Academic Press, London, 1997. [ Links ]
2. C. Bock, B. MacDougall, J. Electroanal. Chem. 491 (2000) 48. [ Links ]
3. L.F. D´Elia, R.L. Ortíz, O.P. Márquez, J. Márquez, Y. Martínez, J. Electrochem. Soc. 148 (2001) 297. [ Links ]
4. M.M. Baizer, H. Lund, Organic Electrochemistry: An Introduction and a Guide, Marcel Dekker, New York, 1990. [ Links ]
5. S. Park, R.J. Gorte, J.M. Vohs, Appl. Catal. A: General 200 (2000) 55.
6. S. Park, M. Vohs, R.J. Gorte, Nature 404 (2000) 265.
7. J.W. Loveland, G.R. Dimeler, Anal. Chem. 33 (1961) 1196. [ Links ]
8. N.L. Weinberg, H.R. Weiberg, Chem. Rev. 68 (1968) 449. [ Links ]
9. S.W. Feldberg, J. Am. Chem. Soc. 88 (1966) 390. [ Links ]
10. D.E. Couch, Electrochim. Acta 9 (1964) 327. [ Links ]
11. S.E. Treimer, J. Feng, M.D. Scholten, D.C. Johnson, A.J. Davenport, J. Electrochem. Soc. 148 (2001) E-459. [ Links ]
12. L.F. D´Elia, L. Rincón, R. Ortíz, Electrochim. Acta 49 (2004) 4197. [ Links ]
13. L.F. D´Elia, L. Rincón, R. Ortíz, Electrochim. Acta 50 (2004) 217. [ Links ]
14. R.J. Gale, Spectroelectrochemistry. Theory and Practice, Plenum Press, New York, 1988. [ Links ]
15. N.M. Pontikos, R.L. McCreery, J. Electroanal. Chem. 324 (1999) 229. [ Links ]
16. A. Bard, R. Parson, J. Jordan, Standard Potential in Aqueous Solution, Marcel Dekker, New York, 1985.
17. Southampton Electrochemistry Group, Instrumental Methods in Electrochemistry, 1st ed., Ellis Horwood, London, 1985. [ Links ]
18. M.S. Ureta-Zarñartu, P. Bustos, C. Berríos, M.C Diez, M.L. Mora, C. Gutiérrez, Electrochim. Acta 47 (2002) 2399. [ Links ]
19. R.H. Wopschall, 20. E. Gileadi, E. Kirowa-Eisner. J. Penciner, Interfacial Electrochemistry. An Experimental Approach, Addison-Wesley, 21. Y. Yang, G. Ling, J. Appl. Electrochem. 25 (1995) 259. [ Links ] 22. T. Davidson, B.S. Pons, A. Bewick, P.P. Schmidt, J. Electroanal. Chem. 125 (1981) 242. [ Links ] 23. S. Pons, T. Davidson, A. Bewick, J. Electroanal. Chem. 160 (1984) 63. [ Links ] 24. S. Pons, T. Davidson, A. Bewick, J. Electroanal. Chem. 140 (1982) 211. [ Links ] 25. P. Krtil, L. Kavan, P. Novák, J. Electrochem. Soc. 140 (1993) 3390. [ Links ] * Corresponding author. E-mail address: delialf@pdvsa.com Present address: Petróleos de Venezuela (PDVSA)-Intevep; Gerencia General de Refinación e Industrialización; Gerencia Técnica de Refinación; Apartado 76343;