ausblenden:
Schlagwörter:
vanadium oxide, silica, water, dispersion, structure, UV-Vis, Raman, XPS, SBA-15
Vanadia in selective oxidation
Zusammenfassung:
Raman, UV-Vis and X-ray photoelectron spectroscopy were combined in one experimental setup to directly study the interplay between structure and dispersion of SBA-15 supported vanadium oxide during dehydration. The fully hydrated catalyst is slightly reduced but consists mainly of V5+ species with pseudo-octahedral V coordination strongly resembling the xerogel V2O5•1.2H2O. After dehydration a highly dispersed surface vanadium oxide species with tetrahedrally coordinated vanadium and significantly smaller ensemble size is formed.