Jump to main content
Jump to site search
Access to RSC content Close the message box

Continue to access RSC content when you are not at your institution. Follow our step-by-step guide.


Issue 7, 2011
Previous Article Next Article

Nature of dispersed vanadium oxide: influence of the silica support structure and synthesis methods

Author affiliations

Abstract

Dispersed vanadium oxide samples were prepared on the basis of two differently structured high surface area silica materials (Aerosil 300, SBA-15). For each support material incipient wetness impregnation and a grafting/ion exchange procedure were applied to prepare catalyst samples with comparable vanadium density. The influence of the silica support material and preparation method on the vanadium oxide structure and dispersion has been studied using diffuse reflectance UV-Vis spectroscopy, visible Raman spectroscopy and X-ray photoelectron spectroscopy (XPS). By independent spectroscopic characterization a fully consistent picture regarding the relation of the structure (UV-Vis, Raman) and dispersion (XPS) is developed. Based on the present structural data and recent findings the dispersed vanadium oxide is proposed to consist of monomers and oligomers with a distorted tetrahedral (VO4) structure containing one short V[double bond, length as m-dash]O bond. A different degree of hydroxylation of vanadium gives rise to two V[double bond, length as m-dash]O stretching bands at 1027 and 1040 cm−1. The structure and dispersion of vanadium oxide are more strongly influenced by the support material than by the synthesis method. In this regard the Aerosil 300 samples show a higher degree of oligomerization, i.e. less dispersion of the surface vanadium oxide species, than the SBA-15 samples. Likewise incipient wetness impregnation leads to more oligomerized species than grafting/ion-exchange.

Graphical abstract: Nature of dispersed vanadium oxide: influence of the silica support structure and synthesis methods

Back to tab navigation

Article information


Submitted
23 Feb 2011
Accepted
30 May 2011
First published
30 Jun 2011

Catal. Sci. Technol., 2011,1, 1175-1181
Article type
Paper

Nature of dispersed vanadium oxide: influence of the silica support structure and synthesis methods

R. Chlosta , G. Tzolova-Müller, R. Schlögl and C. Hess, Catal. Sci. Technol., 2011, 1, 1175
DOI: 10.1039/C1CY00062D

Social activity

Search articles by author

Spotlight

Advertisements