Direct epoxidation of propene over gold-titania catalysts: a transient study of the reaction mechanism

Gold-titania based catalysts for the direct epoxidation of propene provide a clean and simple route for future propene oxide producing processes. These catalysts, producing propene oxide in a single step, have a moderate activity and a very high selectivity towards propene oxide. However, the hydrogen, which is used as a co-reactant, is used less efficient. To be able to improve the hydrogen efficiency as well as the catalyst stability, mechanistic knowledge on the catalyst is essential. A (transient) kinetic study has been performed, aided by in-situ spectroscopic measurements. This study will be presented together with recommendations on how to develop improved catalysts for this system.