Elucidation of Possible Reaction Mechanism and Catalyst Design via Kinetic Modeling: Case Studies in Hydrogenation Reactions

Catalyst materials are typically synthesized with distinct composition, and they are evaluated for their specific reaction in terms of conversion and selectivity. In this respect, it can be anticipated that an intermediate composition often leads to the best catalyst. In order to establish this specific composition, this work presents the practical use of kinetic modeling when typical conversion and selectivity versus reaction time experimental data are provided. Specific examples from catalytic hydrogenation reactions starting from citral, cinnamaldehyde, and dicyclopentadiene are used. In the first two cases, the effect of catalyst composition and the influence of prereduction treatment are linked to kinetic hydrogenation parameters, from which it was clear that, e.g., the prereduction speeds up both desired and unwanted reaction paths. For the latter example, it is shown that extracted kinetic data, together with physical characterizations, such as XPS, and chemical characterization such as H2-TPR, can serve as a basis for optimization of catalyst design leading to possible superior catalytic activity or selectivity.