Chemical structures of ZrO2-supported V-Sb oxides

The effect of the vanadium and/or antimony loading on the structure of zirc onia and zirconium hydroxide on calcination is studied by X-ray diffraction and Raman spectroscopy. Vanadia promotes the transition of tetragonal to m onoclinic zirconia at high temperatures. The interaction of dispersed vanad ium oxide species with a zirconia support leads to the formation of ZrV2O7, which is easier on uncalcined zirconium hydroxide. Antimony tends to stabi lize the tetragonal phase of zirconia and its specific area. The simultaneo us presence of Sb and V on zirconia at Ism coverage leads to a preferential interaction of individual V and Sb oxides on the zirconia surface rather t han the formation of a binary Sb-V oxide. However at high Sb-V coverage, Sb VO4 is formed at the expense of surface Sf oxide, while the transition to m onoclinic polymorph is minimized. Simultaneously, the excess of antimony fo rms alpha -Sb2O4.