Corrosion Protection of Platinum-Based Electrocatalyst by Ruthenium Surface Decoration
journal contributionposted on 12.06.2018, 00:00 by Primož Jovanovič, Marjan Bele, Martin Šala, Francisco Ruiz-Zepeda, Goran Dražić, Nataša Zabukovec Logar, Nejc Hodnik, Miran Gaberšček
A comprehensive insight into the electrochemical performance of PtCu3 electrocatalyst nanoparticles with and without Ru decoration is provided. The online dissolution investigation using the highly sensitive online analytical methodology of electrochemical flow cell coupled to inductively coupled plasma mass spectrometry reveals that the addition of Ru nanoparticles inhibits Pt dissolution presumably because of three effects: (i) suppression of Pt oxide formation, (ii) sacrificial corrosion of Ru, and (iii) lowering of local surface pH. The Ru nanoparticles, however, also lead to a decrease of the amount of crystal structure ordering, which in turn is one of the reasons for the increase of the corrosion of Cu. By measuring the potential of total zero charge it is shown that Ru decoration does not alter the electrochemical properties of the native Pt surface. Finally, Ru decoration of the Pt-based electrocatalyst is shown to present a viable approach to enhance the platinum corrosion resistance, which is confirmed by thin-film rotating disc electrode accelerated degradation tests.