The importance of site isolation and phase cooperation in propane ammoxidation on rutile-type vanadia catalysts
Författare
Summary, in English
Propane ammoxidation to acrylonitrile over rutile-type vanadia catalysts is discussed regarding phase cooperation and site isolation effects. Compared with the pure phases, biphasic catalysts with both similar to SbVO4 and alpha -Sb2O4 are considerably more selective to the formation of acrylonitrile. It is demonstrated that cooperation between the phases during the calcination of the catalyst and the use in propane ammoxidation results in spreading of antimony species from free antimony oxide to the surface of similar to SbVO4, forming Sb5+-V3+/V4+ supra-surface sites being involved in the formation of acrylonitrile. Dilution and isolation of the vanadium centers in similar to SbVO4 through the partial replacement with, e.g., Al, Ti and W improves the catalytic properties. Structure-reactivity correlations using data for a nominal Sb0.9V0.9,TixOy series indicate that the activation of propane occurs on a V3+ site and the activation of ammonia requires an Sb5+ site.
Avdelning/ar
Publiceringsår
2001
Språk
Engelska
Sidor
103-110
Publikation/Tidskrift/Serie
Topics in Catalysis
Volym
15
Issue
2-4
Dokumenttyp
Artikel i tidskrift
Förlag
Springer
Ämne
- Chemical Engineering
Nyckelord
- propane ammoxidation
- Sb-V oxide catalysts
- microstructure
- phase
- cooperation
- site isolation
Status
Published
ISBN/ISSN/Övrigt
- ISSN: 1572-9028