In situ EXAFS study of Pd/Al2O3 during aerobic oxidation of cinnamyl alcohol in an organic solvent

Dynamic structural changes of an alumina-supported palladium catalyst were followed by in situ EXAFS and quick EXAFS (QEXAFS) during oxidative dehydrogenation of cinnamyl alcohol. QEXAFS studies in a continuous flow fixed-bed reactor revealed that the palladium constituent was reduced within 1 h during exposure of the catalyst to a toluenic cinnamyl alcohol flow in Ar. After saturation of the feed with 5% O2/He the product distribution was similar to that observed in a slurry reactor and indicated dehydrogenation, hydrogenation, hydrogenolysis, and decarbonylation reactions, catalyzed by metallic Pd. The studies show that dynamic structural changes and the catalytic performance of an industrial supported metal catalyst in an organic solvent can be monitored simultaneously.