Direct correlation of the dispersion and structure in vanadium oxide supported on silica SBA-15

Raman, UV–vis, and X-ray photoelectron spectroscopy were combined in one experimental setup to directly study the interplay between the 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.