CATALYTIC ACTIVITY AND ELECTRIC RESISTANCE OF EVAPORATED COPPER-NICKEL FILMS

The dependencies of the hydrogenation catalytic activity and electric resistance of copper-nickel films upon the composition of the film were investigated. The film was prepared by the evaporation of copper and nickel metals or their alloys on a substrate cooled by liquid oxygen. Prior to use, the film was treated in a vacuum at 30 ° or 250 °C. The catalytic activity was tested by the hydrogenation reaction of ethylene. The maximum of activity for the reaction was always found in the alloy region of the film, irrespective of the order of the deposition of the two metals, when the film was treated at 30 °C. However, the maximum activity shifted to the pure nickel, when the treatment temperature was raised to 250 °C. The electric resistance of 50% nickel film was always maximum. It was also noted that an increase in treatment temperature resulted in a marked decrease in electric resistance, especially on 50% nickel film. The catalytic activity is discussed in view of the change of the amount of the especially unstable lattice imperfections in the film. © 1969.