Dealloying Studies of Cu₃Pd Single Crystal Surfaces

Abstract

Nano-porous metals formed by dealloying have potential application in a variety of fields such as catalysts, actuators, biomedical sensors and fuel cells. Several aspects of the formation of porous surface during dealloying have not completely been understood. The Cu-Pd system is interesting as a model system for corrosion as well as a potential catalyst material. The initial dealloying and selective dissolution of single-crystals Cu 3 Pd (111) and Cu 3 Pd (100) in 0.1 M H 2 SO 4 in the potential range of 400-800mV has been studied. With in-situ X-ray diffraction (Synchrotron Light), we observed the epitaxial Pd layer peak to appear by increasing the potential close to the critical potential. Exsitu atomic force microscopy (AFM) showed the formation of nanoscale islands of Pd (20-50 nm). Our aim in this project is to study the initial steps of dealloying of well-defined Cu-Pd surfaces on the atomic scale and to compare the results to the Cu-Au system.