Reaction kinetics of cyclohexanone ammoximation over TS-1 catalyst in a microreactor

A continuous flow microfluidic system was developed to evaluate the reaction kinetics of cyclohexanone ammoximation over TS-1 catalyst. An ultrasonic field was introduced to avoid the sedimentation of solid catalyst. Compared with the batch reactor, the microfluidic system provides a more precise control of reaction conditions, faster reactant mixing and enhanced mass transfer. Thus, more accurate kinetic parameters can be extrapolated. The reaction order of each reactant, pre-exponential factor and activation energy were determined. A reaction kinetic model based on the mechanism through hydroxylamine route has been developed under the assumption that the reaction between hydrogen peroxide adsorbed on Ti active sites and free ammonia is the rate-determining step. The model is in good agreement with the experimental results. In addition, it has been proved that the microfluidic system with assistance of ultrasound field could be a good platform for activity evaluation of new nanocatalysts.