Advertisement

Korean Journal of Chemical Engineering

, Volume 22, Issue 6, pp 839–843 | Cite as

Surface chemical structures of CoO x /TiO2 catalysts for continuous wet trichloroethylene oxidation

  • Moon Hyeon Kim
Article

Abstract

An earlier sample of 5% CoO x /TiO2 used for the wet oxidation of TCE at 310 K forca. 6 h has been characterized with a fresh catalystvia XRD and XPS measurements. The binding energy for Co 2p3/2 of the fresh sample appeared at 781.3 eV, which was very similar to the chemical states of CoTiO x such as Co2TiO4 and CoTiO3, whereas the spent catalyst indicated a 780.3-eV main peak for Co 2p3/2 with a satellite structure at a higher energy region. This binding energy was almost equal to that of Co3O4 among reference Co compounds used. The phase structure of Co3O4 was revealed upon XRD measurements for all the catalyst samples. Based on these XPS and XRD results, a surface chemical structure of CoO x species existing with the fresh catalyst can be proposed to be predominantly Co3O4 encapsulated completely by very thin filmlike CoTiO x consisting of Co2TiO4 and/or CoTiO3, with a tiny amount of Co3O4 particles covered partially by such cobalt titanates which may be responsible to the initial catalytic activity. Those CoTiO x overlayers on Co3O4 particles may be readily removed into the wet media within 1 h at 310 K based on our earlier study, thereby giving rapid increase in the catalytic activity for that period.

Key words

Catalytic Wet Oxidation Cobalt Oxides Trichloroethylene Surface Chemical States XPS 

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

References

  1. Brik, Y., Kacimi, M., Ziyad, M. and Bozon-Verduraz, F., “Titania-Supported Cobalt and Cobalt-Phosphorus Catalysts: Characterization and Performances in Ethane Oxidative Dehydrogenation”,J. Catal.,202, 118 (2001).CrossRefGoogle Scholar
  2. Chuang, T. J., Brundle, C. R. and Rice, D. W., “Interpretation of the X-ray Photoemission Spectra of Cobalt Oxides and Cobalt Oxide Surfaces”,Surf. Sci.,59, 413 (1976).CrossRefGoogle Scholar
  3. Drago, R. S., Jurczyk, K., Singh, D. J. and Young, V., “Low-Temperature Deep Oxidation of Hydrocarbons by Metal Oxides Supported on Carbonaceous Materials”,Appl. Catal. B,6, 155 (1995).CrossRefGoogle Scholar
  4. Frydman, A., Castner, D. G., Schmal, M. and Campbell, C. T., “Particle and Phase Thicknesses from XPS Analysis of Supported Bimetallic Catalysts: Calcined Co-Rh/Nb2O5”,J. Catal.,152, 164 (1995).CrossRefGoogle Scholar
  5. Haumodi, S., Larachi, R. and Sayari, A., “Wet Oxidation of Phenolic Solutions over Heterogeneous Catalysts: Degradation Profile and Catalyst Behavior”,J. Catal.,177, 247 (1998).CrossRefGoogle Scholar
  6. Ho, S. W., Cruz, J. M., Houalla, M. and Hercules, D. M., “The Structure and Activity of Titania Supported Cobalt Catalysts”,J. Catal.,135, 173 (1992).CrossRefGoogle Scholar
  7. Hocevar, S., Batista, J. and Levec, J., “Wet Oxidation of Phenol on Ce1-x-CuxO2-d Catalyst”,J. Catal.,184, 39 (1999).CrossRefGoogle Scholar
  8. Hosokawa, S., Kanai, H., Utani, K., Taniguchi, Y. I., Saiti, Y. and Imamura, S., “State of Ru on CeO2 and Its Catalytic Activity in the Wet Oxidation of Acetic Acid”,Appl. Catal. B,45, 181 (1998).CrossRefGoogle Scholar
  9. Kim, M. H. and Choo, K. H., “Catalytic Wet Oxidation of TCE over Supported Metal Oxides”,Theor. Appl. Chem. Eng.,9, 1180 (2004).Google Scholar
  10. Kim, M. H., Ebner, J. R., Friedman, R. M. and Vannice, M. A., “Determination of Metal Dispersion and Surface Composition in Supported Cu-Pt Catalysts”,J. Catal.,208, 381 (2002).CrossRefGoogle Scholar
  11. Kim, J. H. and Lee, H. I., “Effect of Surface Hydroxyl Groups of Pure TiO2 and Modified TiO2 on the Photocatalytic Oxidation of Aqueous Cyanide”,Korean J. Chem. Eng.,21, 116 (2004).CrossRefGoogle Scholar
  12. Kim, M. J., Nam, W. and Han, G.Y., “Photocatalytic Oxidation of Ethyl Alcohol in an Annulus Fluidized Bed Reactor”,Korean J. Chem. Eng.,21, 721 (2004).CrossRefGoogle Scholar
  13. Kim, M. H., Nam, I. S. and Kim, Y.G., “Characteristics of Mordenite-Type Zeolite Catalysts Deactivated by SO2 for the Reduction ofNO with Hydrocarbons”,J. Catal.,179, 350 (1998).CrossRefGoogle Scholar
  14. Krishnamoorthy, S., Rivas, J. A. and Amirdis, M. D., “Catalytic Oxidation of 1,2-Dichlorobenzene over Supported Transition Metal Oxides”,J. Catal.,193, 264 (2000).CrossRefGoogle Scholar
  15. Larachi, F., Iliuta, I. and Belkacemi, K., “Catalytic Wet Air Oxidation with a Deactivating Catalyst Analysis of Fixed and Sparged Three-Phase Reactors”,Catal. Today,64, 309 (2001).CrossRefGoogle Scholar
  16. Lee, G., Rho, S. and Jahng, D., “Design Considerations for Groundwater Remediation using Reduced Metals”,Korean J. Chem. Eng.,21, 621 (2004).CrossRefGoogle Scholar
  17. Pintar, A., “Catalytic Processes for the Purification of Drinking Water and Industrial Effluents”,Catal. Today,77, 451 (2003).CrossRefGoogle Scholar
  18. Pintar, A. and Levec, J., “Catalytic Oxidation of Organics in Aqueous Solutions: I. Kinetics of Phenol Oxidation”,J. Catal.,135, 345 (1992).CrossRefGoogle Scholar
  19. Sadana, A. and Katzer, J. R., “Involvement of Free Radicals in the Aqueous-Phase Catalytic Oxidation of Phenol over Copper Oxide”,J. Catal.,35, 140 (1974).CrossRefGoogle Scholar
  20. Sexton, B. A., Hughes, A. E. and Turney, T. W., “An XPS and TPR Study of the Reduction of Promoted Cobalt-Kieselguhr Fischer-Tropsch Catalysts”,J. Catal.,97, 390 (1986).CrossRefGoogle Scholar
  21. Sidebottom, H. and Franklin, J., “The Atmospheric Fate and Impact of Hydrochlorofluorocarbons and Chlorinated Solvents”,Pure Appl. Chem.,68, 1757 (1996).Google Scholar
  22. Silva, A. M. T., Marques, R. R. N. and Quinta-Ferreira, R. M., “Catalysts Based in Cerium Oxide for Wet Oxidation of Acrylic Acid in the Prevention of EnvironmentalRisks”,Appl. Catal. B,47, 269 (2004).CrossRefGoogle Scholar
  23. Thormahlen, P., Skoglundh, M., Fridell, E. and Andersson, B., “Low-Temperature CO Oxidation over Platinum and Cobalt Oxide Catalysts”,J. Catal.,188, 300 (1999).CrossRefGoogle Scholar
  24. Venezia, A. M., “X-ray Photoelectron Spectroscopy (XPS) for Catalysts Characterization”,Catal. Today,77, 359 (2003).CrossRefGoogle Scholar
  25. VoΒ, M., Borgmann, D. and Wedler, G., “Characterization of Alumina, Silica, and Titania Supported Cobalt Catalysts”,J. Catal.,212, 10 (2002).CrossRefGoogle Scholar
  26. Yankin, A., Vikhreva, O. and Balakirev, V., “P-T-x Diagram of the Co-Ti-O System”,J. Phys. Chem. Solids,60, 139 (1999).CrossRefGoogle Scholar
  27. Yao, Y. F. Y., “The Oxidation of Hydrocarbons and CO over Metal Oxides: III. Co3O4”,J. Catal.,33, 108 (1974).CrossRefGoogle Scholar

Copyright information

© Korean Institute of Chemical Engineering 2005

Authors and Affiliations

  1. 1.Department of Environmental EngineeringDaegu UniversityGyeongsanKorea

Personalised recommendations