Catalysts for oxidative dehydrogenation of isobutyric acid

The catalytic oxidative dehydrogenation of isobutyric acid has been studied with an Mo-V-P oxide catalyst coated on Aerosil. The oxidation main products involve methacrylic acid, acetone, propylene, and CO2. Lowering of the oxidation state of vanadium in the catalyst to V-IV is connected with a distinct decrease in the catalyst activity and its selectivity for methacrylic acid. Increasing phosphorous content in the catalyst causes a mild increase in its activity along with an increased yield of methacrylic acid. A modification of the said catalyst with cobalt results in its activity decrease and lowers the yield of methacrylic acid. By means of IR spectroscopy it has been found that isobutyric and methacrylic acids are adsorbed on the surface of the catalysts studied already at room temperature, which is connected with formation of the corresponding carboxylates.