Investigation of the transformations of chlorobenzene at the surface of a vanadium oxide catalyst by IR spectroscopic and thermal desorption methods
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In the present work an IR spectroscopic and thermodesorption investigation of the surface compounds formed by chlorobenzene on a vanadium oxide catalyst was undertaken. It was established that in the initial period of adsorption chlorobenzene forms a weakly bonded π complex with the surface of the catalyst. With subsequent increase in temperature a compound firmly bound to the surface of the catalyst appears. It is most likely that this complex is a σ complex formed through a bond between the reagent molecule and an electrophilic center on the surface. On the basis of the results from the IR-spectroscopic investigations and thermal desorption a mechanism involving intermediate surface compounds detected by IR spectroscopy is proposed for the catalytic oxidation of chlorobenzene.
KeywordsOxide Spectroscopy Vanadium Initial Period Oxide Catalyst
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- 1.Yu. V. Belokopytov, Yu. N. Grebennikov, Yu. I. Pyatnitskii, and A. I. Telyatnik, “Investigation of the reaction of benzene with vanadium-molybdenum catalyst by programed thermal desorption,” Katal. Katal. No. 21, 57–63 (1983).Google Scholar
- 2.L. M. Sverdlov, M. A. Kovner, and E. P. Krainov, Vibrational Spectra of Molecules [in Russian], Nauka, Moscow (1970).Google Scholar
- 3.P. W. Selwood, “The mechanism of chemisorption; benzene and cyclohexene on nickel and the catalytic hydrogenation of benzene,” J. Am. Chem. Soc., 75, 4637–4640 (1957).Google Scholar
- 4.J. L. Garnett and W. A. Sollich, “Deuterium exchange reactions with substituted aromatics,” Aust. J. Chem., 14, No. 3, 441–448 (1961).Google Scholar
- 5.H. Ohtani, M. A. Van Hove, and G. A. Somorjai, “Molecular structure of benzene coadsorbed with CO on Pd 9 (111); a dynamic low energy electron diffraction analysis,” J. Phys. Chem., 92, No. 13, 3974–3982 (1988).Google Scholar
- 6.A. A. Davydov, “Nature of oxide sites and the role in the formation of the toluene complexes,” Mater. Chem. Phys., 19, No. 1, 97–112 (1988).Google Scholar
- 7.A. A. Davydov, IR Spectra in the Surface Chemistry of Oxides [in Russian], Nauka, Novosibirsk (1984).Google Scholar
- 8.A. Ramstetter and A. Baerns, “Infrared spectroscopic investigation of the adsorption states of the 1-butene, 1-butadiene, furan, 2,5H-furanone, and maleic anhydride on alumina-supported V2O5-P2O5 catalyst,” J. Catal., 109, 303–313 (1988).Google Scholar
- 9.A. G. Anshits, V. D. Sokolovskii, G. K. Boreskov, et al., Kinet. Katal., 16, No. 1, 95–102 (1975).Google Scholar
- 10.A. A. Davydov, “Investigation of the adsorption of hydrocarbons on oxide catalysts by IR spectroscopy. 15. Reaction of hydrocarbons on V2O/Al2O3,” Kinet. Katal., 31, No. 1, 100–105 (1990).Google Scholar
- 11.G. I. Golodets, Heterogeneous-Catalytic Oxidation of Organic Materials [in Russian], Nauka Dumka, Kiev (1978).Google Scholar