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Structure and Reactivity of Vanadium and Molybdenum Oxide‐Based Catalysts Supported on MgO‐Coated SBA‐15
Author(s) -
Scholz Juliane,
Ressler Thorsten
Publication year - 2012
Publication title -
zeitschrift für anorganische und allgemeine chemie
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.354
H-Index - 66
eISSN - 1521-3749
pISSN - 0044-2313
DOI - 10.1002/zaac.201204127
Subject(s) - humanities , art , physics
Supported metal oxides constitute model systems for investigating catalyst structure and performance. The structure of the surface catalysts is significantly affected by the properties of the support. Here, we investigated the influence of MgO-coated SBA-15 (MgO/SBA-15) with basic surface properties on the structure of vanadium and molybdenum oxide catalysts. X-ray absorption spectroscopy (XAS) and diffuse reflectance UV/Vis spectroscopy measurements showed that a similar structural motif was obtained for VOx and MoOx supported on MgO/SBA-15 at comparable catalyst loadings. The V and Mo species exhibited a tetrahedral arrangement of oxygen atoms around the metal centers. During calcination the formation of Mo dimers was observed. Supported V oxides formed dimers or chains at higher loadings. However, the connectivity of the catalyst units was low compared to oxides supported on SBA-15.[1,2] Activity in selective oxidation of propene was directly correlated to the number of bridging M–O–M bonds. A comparison of the V and Mo oxides showed a trend which was assigned to chemical composition rather than structural effects. We acknowledge HASYLAB and DFG for providing beamtime and financial support, respectively.