Cyclohexane dehydrogenation on a copper-platinum catalyst

The reaction of the dehydrogenation of cyclohexane on a copper-platinum catalyst supported by silica gel (1 wt % Pt + 0.15 wt % Cu)/SiO 2 was studied. The state of the catalyst surface was investigated using X-ray photoelectron spectroscopy. It was established that under both flow and static conditions, the activity of the copper-platinum catalyst is higher than the activity of a catalyst containing 1 wt % Pt/SiO 2. The rise in activity as a result of the introduction of copper, due to a decrease in the activation energy, is explained by an increase in the fraction of carbon in the composition of active centers localized on particles of neutral (Pt m 0 ) and positively charged (Pt n +δ ) platinum, and by the formation of centers with increased activity as a result of the adsorption of Cu +δ on particles of Pt m 0 . It was demonstrated that treating the copper-platinum catalyst with the plasma of a glow discharge in argon and oxygen increases its activity, while treatment in high-frequency H 2 plasma reduces it. The indicated changes in the activity are associated with the alteration of the activation energies and the number of active centers, revealed by X-ray photoelectron spectroscopy, that depend on changes in the catalyst surface composition. © 2010 Pleiades Publishing, Ltd.