OXIDATIVE AMMONOLYSIS OF 4-METHYLPYRIDINE ON OXIDE VANADIUM-TITANIUM-ZIRCONIUM CATALYST MODIFIED BY TIN AND TUNGSTEN OXIDES

Catalysts based on vanadium pentoxide modified by Ti, Sn, Zr and W oxides were tested in the oxidative ammonolysis of 4-methylpyridine. The role of the main process parameters such as temperature, the ratio of the initial components in the conversion of the methyl group to the nitrile one, and the optimal conditions for the oxidative ammonolysis of 4-methylpyridine were determined. It is determined that the V-Ti-Zr-O-catalyst and the sample containing 9% of tungsten oxide are superior in catalytic activity to the V-Ti-Zr-Sn-O contact. Conditions that ensure a high selectivity for the formation of 4-cyanopyridine were found. The highest yield of the target product (85-86%) was obtained on V-Ti-Zr-W-O at 270 °C, and the yield of 4-cyanopyridine was 87.5% at 310° C on the V-Ti-Zr-Sn-O catalyst. The phase composition and structural changes occurring in modified vanadium oxide catalysts have been studied. It is determined that mixed V-Ti-Zr-Sn-O and V-Ti-Zr-W-O catalysts contain ZrV2O7, the monoclinic modification of ZrO2 (baddeleyite), TiO2 (anatase), SnO2, WO3, and V2O5. In catalysts, it can exist in small amounts as a separate VO2 phase. The V-Ti-Zr-W-O catalyst showed the best catalytic properties. It has highactivity and selectivity towards 4-cyanopyridine.

Oxidative ammonolysis of 3,4-dimethylpyridine on the vanadium oxide catalysts

Oxidative ammonolysis of 3,4-dimethylpyridine on an individual vanadium oxide (V2O5) catalyst and binary vanadium oxide catalysts, modified by additions of SnO2 and ZrO2, has been studied. A connection between ??- acidity of the methyl groups of the substrate in the gaseous phase and in the chemosorbed state and the sequence of their transformation into a cyano group has been established. It has been shown that nucleophilicity of vanadyl oxygen, calculated by the Density Functional Theory method, increases with V2O5 modification by SnO2 and ZrO2 additions. Herewith, an increasing yield of 3- methyl-4-cyanopyridine and imide of pyridine-3,4-dicarboxylic acid was observed. A proposed mechanism of the imide of pyridine-3,4-dicarboxylic acid formation has been discussed

Kinetics of mechanochemical processing of secondary plant raw in humic acid

The kinetics of the preparation of humic acids from peat and from the products of mechanochemical synthesis and oxidative ammonolysis of wood biomass in conditions of ultrasonic treatment of aqueousalkaline media was studied. It is shown that this process is described by a kinetic equation of the second order and limited the intensity of ultrasonic treatment.