Effect of plasmochemical treatment of platinum catalyst on dispersity of metal phase and its catalytic activity

We studied how treatment of 0.64 wt % Pt/SiO2 catalyst with a glow-discharge plasma in O2 and a high-frequency plasma in H 2 (HF H2) influences the cyclohexane dehydrogenation reaction. The effect of plasmochemical treatment on the average diameter of platinum particles was established by the method of X-ray diffraction analysis. It was found that oxygen plasma increases the surface area of the metal by ∼15% and diminishes activity by raising the activation energy and reducing the number of active centers per unit surface of the metal. The HF H2 plasma increases the reaction rate constant many times over, due to the number of active centers per unit surface of the metal rising sharply while the size of the Pt particles remains unchanged. © Pleiades Publishing, Ltd., 2010