Electrochemical dissolution of noble metals native oxides

Abstract

In electrocatalysis, noble metals are used as supported nanoparticles. Concerns regarding their stability in an anodic acidic environment are well documented. In this work we show that also cathodic dissolution of the noble metal native oxides formed during relatively shorts exposures to air must be considered in the estimation of the overall catalyst degradation. It is found that cathodic dissolution decreases in the order of Ru>Rh>Ir>Pt. As Au does not oxidize in air, no cathodic Au dissolution is recorded. Physical properties of metals related to cathodic dissolution are shortly discussed.