Dependence of the catalytic activity of palladium-ruthenium alloys on their composition and conditions of heat treatment

1. The catalytic activity of binary alloys of palladium containing 4.4–9.2% Ru was investigated as a function of' the conditions of their heat treatment in an atmosphere of various gases (air, H2, Ar). 2. The results of the investigation were treated according to a program permitting calculation of the parameters of the Arrhenius equation on the assumption of normal and logarithmic-normal distributions of their values. The correctness of the hypothesis of a logarithmic-normal distribution was demonstrated. 3. Raising the temperature of treatment of the alloys in a stream of air from 350 to 750°, as well as repeated treatment in a stream of air at 750°, caused an appreciable increase in the catalytic activity, associated with an increase in the preexponential factors. An even greater increase in the activity, due to a decrease in the activation energy, is also achieved as a result of treatment of the catalyst with air, and then with H2, at 750° with rapid cooling in H2.