Electrolytic preparation of fine Pd-Ag powders of any given chemical composition

Abstract

1. A study was made of the continuous electrolytic preparation of Pd-Ag powders of any desired composition, involving the use of an insoluble anode and constant electrolyte circulation. 2. The effects of various electrolysis parameters (cathodic current density, solution concentration and acidity, and the ratio of component concentrations in the electrolyte) upon the powder current efficiency, composition, and particle size were investigated. It was established that the powder current efficiency grows with decrease in cathodic current density, increase in total Ag+ Pd concentration in the solution, and rise in temperature, but is independent of pH and the Pd/Ag ratio of the solution. 3. The Pd/Ag ratios of the solution and the powder closely match when the cathodic process takes place under conditions of diffusional kinetics. 4. The particle size of the resultant powder diminishes with increase in cathodic current density, decrease in overall Ag-Pd concentration in the solution, fall in temperature, rise in pH, and growth in the relative palladium content of the solution. 5. Within the whole range of component concentrations, the electrolytic Ag-Pd powders obtained are solid solutions of the two metals.