Selective oxidation of isobutene over multicomponent molybdate catalyst

The kinetics of the selective oxidation of isobutene to methacrolein over multicomponent molybdate catalyst were investigated in a differential tubular flow reactor at low conversion levels. The study was carried out over the temperature range 609 to 694 K. The data were fitted to a number of standard kinetic models based on Mars-van Krevelen and Langmuir-Hinshelwood mechanisms, and also to the empirical power rate law model. The kinetics of the formation of methacrolein were best represented by the redox model in which non-dissociated oxygen is involved in the reoxidation step. The rate determining step was found to be the catalyst reduction with an energy of activation of 177 kJ/mol. The activation energy for catalyst reoxidation is found to be 71 kJ/mol.