Electrochemical surface science of platinum electrodes

First, the double-layer structure and surface chemistry on platinum is highly structure and electrolyte sensitive, with steps and defects being oxidized already in what is classically assumed to be hydrogen region. Second, the roughening occurring during oxidation and reduction cycling is imaged using in situ electrochemical STM, demonstrating an important role of nano-island formation and step meandering. Finally, at sufficiently negative potential, platinum undergoes anisotropic cathodic corrosion, as illustrated by ex situ SEM and in situ electrochemical AFM. X-Ray spectroscopy and DFT calculations suggest a crucial role for ternary metal hydrides as the key cathodic corrosion intermediate.