Gold's hidden weakness: scientists map how different crystal faces rust differently
Researchers have identified that gold electrodes oxidize at different rates depending on their crystal orientation—a finding that could reshape design of catalysts for fuel cells, water splitting, and chemical manufacturing. The real-time imaging technique reveals how realistic industrial electrodes behave under stress, moving beyond oversimplified lab models to predict durability and performance in harsh operating conditions.
Originaltitel: Surface orientation-dependent electro-oxidation of a polycrystalline gold electrode
<p>The activity and stability of an electrocatalyst is governed by the structural and chemical changes occurring at the solid-liquid interface. While single crystal electrodes have often served as model systems to elucidate structure-function relationships, extending these insights to more realistic polycrystalline electrodes requires experimental techniques with spatial resolution that can operate under electrochemical conditions. Herein, the electro-oxidation of a polycrystalline gold electrode is investigated in situ using two-dimensional surface optical reflectance, electrochemical near ambient pressure X-ray photoelectron spectroscopy, and tomographic surface X-ray diffraction. This combination of techniques provides surface-sensitive chemical and structural information. In the case of the polycrystalline gold, a surface orientation-dependent oxidation behaviour is found where both the onset and growth of oxides/hydroxides are affected. Our approach provides an enhanced understanding of the dynamic behaviour of complex electrodes under harsh environments, enabling grain-resolved insight into electrochemical processes.</p>