Specific Features of the Catalytic Hydrogenation of the Norbornadiene-Based Carbocyclic Compounds

The gas- and liquid-phase hydrogenation of bicyclo[2.2.1]hepta-2,5-diene (norbornadiene) in the presence of the Pd/γ-Al2O3 (PK-25) industrial palladium catalyst in an n-heptane medium at 75–200°С is studied. The reaction products are identified, the main reaction routes are established, and the material balance is studied. The effect of preferable adsorption of norbornadiene compared to other components of the system on the palladium active site is confirmed. A relationship between possible modes of norbornadiene coordination and the product structure is considered. A parallel-sequential scheme is proposed for the mechanism of the process on the basis of the obtained experimental and theoretical data.