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Portrait of Reine Wallenberg. Photo: Kennet Ruona

Reine Wallenberg

Professor, Coordinator Materials Science

Portrait of Reine Wallenberg. Photo: Kennet Ruona

Vanadium Oxide on TiO2(B) - a HREM Study of Catalysis by Support Interaction

Author

  • Reine Wallenberg
  • Arne Andersson
  • Mehri Sanati

Summary, in English

A model catalyst system with a loading range between 1/4 to 10 theoretical layers of vanadium oxide on TiO2(B ) support was tried for selective ammoxidation and oxidation of toluene. In the case of ammoxidation, a peak in conversion rate per unit surface area was found for a catalyst with a coverage of about 2 theoretical layers, indicating a strong interaction between the catalyst and the otherwise inactive support. The presence and amount of vanadium oxide on the support surface was verified by diffuse reflectance infrared spectroscopy, energy-dispersive elemental X-ray mapping and chemical analysis. By high resolution electron microscopy, the 32~ volume loss of the K2Ti409 support precursor on calcination was shown to be achieved by formation of microscopic, facetted voids ("negative crystals") in the bulk of the material. Initially, surfaces appeared dean and without any anomalous surface features. This can be explained by similar scattering power of V and Ti, and similar structure types. However, the active phase could be "developed" to visibility by prolonged exposure to the electron beam, which produced 1-2 am particles of reduced vanadium oxides on the surface.

Department/s

  • Centre for Analysis and Synthesis
  • Department of Chemical Engineering
  • Ergonomics and Aerosol Technology

Publishing year

1990

Language

English

Pages

33-40

Publication/Series

Ultramicroscopy

Volume

34

Issue

1-2

Document type

Journal article

Publisher

Elsevier

Topic

  • Chemical Sciences
  • Chemical Engineering
  • Production Engineering, Human Work Science and Ergonomics

Status

Published

ISBN/ISSN/Other

  • ISSN: 0304-3991