Abstract
Current research on the synthesis of isonicotinic acid (INA) has focused on the development of catalysts by mixing transition metal oxides such as vanadium, titanium and zirconium in the desired molar ratio. These materials have good catalytic activity (CA) but have drawbacks, including low resistance to deactivation and limited ability to control reaction selectivity. In the present study, two- and three-component catalysts containing vanadium were successfully synthesized and their compositions and properties were studied. The experimental results showed that the efficiency of V-Ti-Mn-O catalyst was superior to V-Ti-O. Selectivity analysis showed that V-Ti-Mn-O was the most efficient catalyst, reaching a maximum value of 67.17% at 320 °C. Scanning electron microscope (SEM), Raman spectroscopy and X-ray diffraction (XRD) were used to characterize the catalysts. The corresponding experimental results showed that the superior performance of the V-Ti-Mn-O catalyst was attributed to both the smaller size of the catalyst particles and their more uniform distribution. In the oxidation of 4-methylpyridine (4-MP), the V-Ti-O catalyst showed lower CA and stability compared to the V-Ti-Mn-O catalyst, which can be attributed to its limited CA and potential deactivation at higher temperatures, probably due to excessive oxidation.