| Article ID | Journal | Published Year | Pages | File Type |
|---|---|---|---|---|
| 68901 | Journal of Molecular Catalysis A: Chemical | 2006 | 7 Pages |
This investigation reports the influence of MoO3 on the dispersion of vanadium oxide on zirconia support. Samples containing various MoO3 loadings ranging from 0.5 to 4 wt.% were prepared by impregnation of previously prepared 6 wt.% V2O5/ZrO2 with requisite amounts of ammonium heptamolybdate solution. Dispersion of vanadia was determined by oxygen chemisorption at 640 K and was found to decrease with the increase of molybdena loading. The calcined catalyst samples were characterized by specific BET surface area, XRD, FT-IR, Oxygen chemisorption and TPR of H2 techniques. The XRD results show that the intensity of tetragonal phase decreases and monoclinic phase intensity increases with the addition of MoO3 to V2O5/ZrO2 catalyst. The TPR of H2 results reveal that the reducibility of vanadia was found to decrease with the addition of molybdena to V2O5/ZrO2 catalyst. The catalytic properties were evaluated during the ammoxidation of 3-picoline to nicotinonitrile. The activity in ammoxidation reaction did not change much with the addition of molybdenum oxide. However, the selectivity of nicotinonitrile was found to increase with molybdena loading, indicates that the added molybdena created additional sites for the ammoxidation of 3-picoline reaction. The addition of molybdenum oxide inhibited the interaction between vanadium and zirconia, leading to decrease in dispersion and reducibility of vanadia.
Graphical abstractZrO2 is an interesting support to investigate the dispersion of vanadia and catalytic properties of V2O5–MoO3 catalysts. This paper provides influence of MoO3 on the dispersion and catalytic properties of vanadium oxide supported on ZrO2. These catalysts are found to be highly active and selective for the vapour phase ammoxidation of 3-picoline to nicotinonitrile. Figure optionsDownload full-size imageDownload as PowerPoint slide
