Selective Anodic Dissolution of an Ag0.58Au0.37Pd0.05 Alloy in Molten Alkali Metal Chlorides over a Wide Temperature Range

The formation of microporous metal structures during the electrochemical dealloying of a single-phase Ag0.58Au0.37Pd0.05 alloy in the following molten salts is investigated: in the LiCl0.57CsCl0.26KCl0.17 at a temperature of 306°C and in CsCl0.455KCl0.245NaCl0.30 + 3 mol % AgCl at 510, 600, 700, and 815°C. The electrolysis potentials are chosen using potentiodynamic curves. As a result of selective anodic dissolution in the potentiostatic mode, typical mutually continuous structures with pore and ligament sizes of 0.5–10 μm are formed. The appearance of pores can be traced up to 815°C, but their specific density on the surface is significantly decreased. An increase in the process temperature causes coarsening or recrystallization of the porous structure, an increase in the pore size, and a decrease in the selectivity of silver dissolution. Almost complete removal of silver from the alloy is achieved at the lowest temperature (306°C) as a result of anodic dissolution at a potential of 0.6 V relative to a silver chloride reference electrode (Ag/LiCl0.57CsCl0.26KCl0.17 + 3 mol % AgCl).