Synthesis of a Pd2In–Pd3In bi-continuous nanoporous structure by electrochemical dealloying in molten salts

Abstract

A study of the high-temperature electrochemical selective dissolution of PdIn intermetallics in molten mixtures of alkali chlorides with the formation of nanoporous structures has been carried out to obtain a coherent structure consisting of Pd₂In and Pd₃In intermetallics. The smallest pore size (approximately 100 nanometers) with a bi-continuous structure of Pd₂In–Pd₃In is obtained from the PdIn intermetallic phase at a temperature of 450 °C and a current density of 50 mA cm⁻² in a molten LiCl–KCl eutectic. It has been shown that the temperature of the anodic dissolution process is the most important factor in controlling the pore size and structural morphology. The morphology of pores and ligaments in the sample at 600 °C is a 3D hierarchy with pore sizes from several hundred nanometers to a micron-scale but with the same Pd₂In–Pd₃In (2 : 1) composition.