High temperature preparation of vanadium phosphate catalysts using water as solvent

J A Lopez-Sanchez, L Griesel, J K Bartley, Richard Peter Kerwin Wells, A Liskowski, D S Su, R Schlogl, J C Volta, G J Hutchings

Research output: Contribution to journalArticle

20 Citations (Scopus)

Abstract

Vanadium phosphate catalysts prepared in aqueous solution at elevated temperature ( 145 degreesC) using either H3PO3 or V2O4 as reactants are described and discussed. This methodology produces catalysts with a much higher surface area (ca. 20 m(2) g(-1)) compared with those prepared using aqueous routes using HCl as reducing agent (ca. 4 m(2) g(-1)). The materials were characterised using a combination of powder XRD, BET surface area measurement, laser Raman spectroscopy, TGA, electron microscopy and P-31 spin echo mapping NMR spectroscopy. Refluxing the precursors in water prior to activation was crucial in obtaining high surface area materials, and P-31 spin echo mapping NMR together with electron microscopy data indicate that the water reflux step influences the relative amounts of V4+ and V5+ phases present in the catalyst, as well as reducing the size of the crystallites. A correlation between the activity of the catalyst and the surface area is observed. However, a small group of catalysts display a higher activity than that expected from this correlation, and this increased activity is discussed in terms of the interaction of V4+ and V5+ phases.

Original languageEnglish
Pages (from-to)3525-3533
Number of pages9
JournalPhysical Chemistry Chemical Physics
Volume5
Issue number16
DOIs
Publication statusPublished - 2003

Keywords

  • phosphorus oxide catalysts
  • butane partial oxidation
  • N-butane
  • maleic-anhydride
  • selective oxidation
  • activation method
  • VPO catalysts
  • mechanochemistry
  • transformation
  • pyrophosphate

Cite this

Lopez-Sanchez, J. A., Griesel, L., Bartley, J. K., Wells, R. P. K., Liskowski, A., Su, D. S., ... Hutchings, G. J. (2003). High temperature preparation of vanadium phosphate catalysts using water as solvent. Physical Chemistry Chemical Physics, 5(16), 3525-3533. https://doi.org/10.1039/b305437n