Effect of potassium on the physicochemical properties of molybdenum oxide catalyst supported on sol-gel alumina-zirconia

Koc S., Gurdag G., Loffler E., Orbay M., Muhler M.

MATERIALS CHEMISTRY AND PHYSICS, vol.86, pp.315-319, 2004 (SCI-Expanded) identifier identifier


Potassium-promoted molybdenum oxide/alumina-zirconia catalysts were prepared by the sol-gel method. The catalysts were characterized by nitrogen physisorption, X-ray diffraction, scanning electron microscopy, Raman spectroscopy, and Fourier transform spectroscopy measurements. It was observed that potassium addition did not drastically disturb the textural properties and led to a redispersion of the molybdenum oxides composed both of octahedral and tetrahedral structures. Molybdenum oxide mainly led to the formation of Bronsted acid centers while alumina-zirconia support contained Lewis acid centers. Potassium led to a decrease in the number of Bronsted acid centers rather than that of Lewis centers. (C) 2004 Elsevier B.V. All rights reserved.