<p>An increase of effectivity of binary and ternary vanadium containing oxide catalysts can be achieved by a regulation of chemical and phase catalyst composition during their preparation. Activity and selectivity of V-Ti catalysts depend on the ratio of V<sub>2</sub>O<sub>5</sub> to VO<sub>2</sub> in the succession of substitutional solid solutions VO<sub>2</sub>- TiO<sub>2</sub>, as well as on the crystal modification of TiO<sub>2</sub>. It was investigated the influence of vanadium oxides over the rate of the polymorfous conversion from anatase to rutile and the kind of TiO<sub>2</sub> crystal modification over V<sub>2</sub>O<sub>5</sub> reduction degree during the thermal treatment of V-Ti catalysts. The synthesized catalysts offered producing nicotinonitrile from 3-methylpyridine with 93-95% mol. yield. Modifying of V-Ti catalysts by SnO<sub>2</sub> increased their activity. The reason is V=O bond weakening under the influence of SnO<sub>2</sub>. That was verified by increasing of V<sub>2</sub>O<sub>5</sub> dissociation rate almost by an order in comparison with V-Ti catalysts. SnO<sub>2</sub> in the ternary catalysts exists as individual phase and acts as a donor of oxygen for the lower vanadium oxides. It provides the high stability of V-Ti-Sn catalysts and possibility of obtaining isonicotinonitrile with 95-97% mol. yield from 4-methylpyridine. The investigation of the mutual influence of starting components in the ternary V-Ti-Zr catalysts showed that ZrO<sub>2</sub> prevented the polymorphous transformation from anatase into rutile. In its turn, anatase stabilized baddeleyite, which has a higher catalytic activity than ruffite. Taking into account the mutual influence of the components, it was able to prepare the selective V-Ti-Zr catalyst. It offered obtaining nicotininitrile from 3-methylpyridine with 92-96% mol. yield. </p>
<p>A chemical composition of V-Ti oxide catalyst changes in accordance with the reaction medium composition in a process of 2-methyl-5-ethylpyrydine ammoxidation into nicotinonitrile in an integral reactor. The presence of alkylpyridine concentration gradient along the catalyst bed leads to the appearance of V<sub>2</sub>O<sub>5</sub> content gradient in the catalyst. V<sub>2</sub>O<sub>5</sub> concentration increases in the conditions of alkylpyridine completed conversion in consequence of oxidative decomposition of VO<sub>2</sub>-TiO<sub>2</sub> solid solution under the influence of N2O nitrogen oxide, which is formed upon the NH<sub>3</sub> oxidation. An increase of V<sub>2</sub>O<sub>5</sub> contents over 5 wt% causes rising of the share of the 2-methyl-5-ethylpyridine and nicotinonitrile destructive oxidation. An introduction of small amounts of alkylpyridine directly into the catalyst bed permits to create the definite alkylpyridine concentration gradient, which the optimal content of V<sub>2</sub>O<sub>5</sub> is corresponding to, for any given conditions of oxidative reaction. The catalysts containing 1-5 wt% of V<sub>2</sub>O<sub>5</sub> and solid solution of VO<sub>2</sub>-TiO<sub>2</sub> possess of the highest selectivity to nicotinonitrile.</p>
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