Physicochemical characterization of WO3/ZrO2 and WO3/Nb2O5 catalysts and their photoactivity for 4-nitrophenol photooxidation in aqueous dispersion
- 345 Downloads
Two different photo-catalysts consisting of tungsten oxide supported on zirconia and niobia have been studied. The photoactivity of the samples has been investigated in both the absence and presence of H2O2 for the photo-oxidation of 4-nitrophenol in aqueous suspensions and compared to that of WO3 and of the pure ZrO2 and Nb2O5 supports. Both catalysts were found to be photoactive, although no beneficial influence of the presence of tungsten oxide on the reaction rate was observed in the absence of H2O2. The presence of hydrogen peroxide was observed to be beneficial for all of the samples. Scanning electron microscopy, X-ray diffraction, diffuse reflectance and laser Raman spectroscopies, surface area and porosity determination, as well as Fourier transform infra-red spectroscopy monitoring of surface acidity were used to characterize the catalysts.
KeywordsZirconia Acid Site Tungsten Oxide Surface Acidity Bare Support
Unable to display preview. Download preview PDF.
- 5.J. C. MOL and J. A. MOULIJN, in “Catalysis, science and technology”, edited by J. R. anderson and M. Boundart Springer Verlag, Berlin, 1987.Google Scholar
- 12.ASTM Powder Diffraction Files, cards no. 17–923 and 37–1484.Google Scholar
- 14.ASTM Powder Diffraction Files, card. no. 7–061.Google Scholar
- 17.J. C. P. BROEKHOFF and B. G. LINSEN, in “Physical and chemical aspects of adsorbents and catalysts”, edited by B. G. Linsen (Academic Press, New York, 1970) p. 1.Google Scholar
- 18.N. NAKAMOTO, “Infrared and Raman spectra of inorganic and co-ordination compounds” (Wiley, New York, 1978).Google Scholar
- 21.I. R. BEATTIE and T. R. GILSON, J. Chem. Soc. A (1969) 2322.Google Scholar
- 23.H. KNÖZINGER, Adv. Catal. 25 (1976) 184.Google Scholar
- 24.H. A. BENES and B. H. C. WINQUIST, ibid. 27 (1978) 97.Google Scholar
- 30.F. DI QUARTO, S. PIAZZA, C. SUNSERI, in “Modification of passive films”, edited by P. Marcus, B. Baroux and M. Keddam (The Institute of Materials, Paris, 1994) p. 76.Google Scholar
- 32.V. AUGUGLIARO, E. DAVÌ, L. PALMISANO, M. SCHIAVELLO and A. SCLAFANI, in “Environmental contamination”, edited by A. A. Orio (CEP Consultants, Edinburgh, 1988) p. 206.Google Scholar
- 33.K. TANAKA, T. HISANAGA and K. HARADA, New. J. Chem. 13 (1989) 5.Google Scholar