Study of the competition between disproportionation and oxidation of cyclohexene in the liquid phase over solid catalysts

A study has been made of the liquid phase conversion of cyclohexene over metallic palladium and platinum catalysts under oxygen and nitrogen atmosphere. Special attention has been given to the effect of oxygen pressure, catalyst support, solvent and metal modifiers on the activity of metal catalysts and distribution of products. In every case the main reaction pathway is disproportionation of cyclohexene to benzene and cyclohexane. Formation of oxygenated products is low even at 2–6 atm of oxygen. Doping of Pd and Pt catalysts with metal modifiers strongly suppresses the conversion of cyclohexene and has no influence on the ratio of benzene/cyclohexane at experiments carried out in an inert atmosphere. An interpretation of these effects is presented.