The effect of water on the structure of supported vanadium oxide structures. An FT-RAMAN, in situ DRIFT and in situ UV-VIS diffuse reflectance study

A promising way to create supported metal oxide catalysts consists of the irreversible adsorption and subsequent thermolysis of metal acetylacetonate complexes. Spectroscopic techniques are often used in the evaluation and assessment of the final catalytic surface structure. In this paper, the use of FT-RAMAN, in situ UV-VIS diffuse reflectance DRS and in situ diffuse reflectance infrared spectroscopy is discussed in the evaluation of silica supported VOx structures. It is argued that water drastically influences the surface structure of these catalysts. It's effects are noticeable in the stages of pretreatment of the support, the actual synthesis and in the post-synthesis storage of the catalyst. (C) 1997 Elsevier Science B.V.