Degradation of Bimetallic Model Electrocatalysts: An In Situ X‐Ray Absorption Spectroscopy Study

Gold support destabilizes platinum: Driven by the low surface energy of Au, a Pt fuel cell catalyst is removed from the surface of the Au support. Depending on the electrochemical potential, this removal can occur through Pt dissolution either into the Au substrate or into the electrolyte (see picture). In situ HERFD XAS measurements indicate formation of PtO2 by a dissolution–precipitation mechanism. Detailed facts of importance to specialist readers are published as ”Supporting Information”. Such documents are peer-reviewed, but not copy-edited or typeset. They are made available as submitted by the authors. Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.