Electrochemical methods for restructuring of metal surfaces: mechanisms and strategies for tailoring free-standing electrocatalysts

Electrocatalysis is driven by the chemical nature of electrodes and their surfaces. Furthermore, the electrocatalytic activity and selectivity critically depend on the atomic surface arrangement of electrodes, characterized by facets and their crystallographic orientation, surface steps, and defects, i.e., the electrode surface structure. Over the past decades, single-crystal studies have provided fundamental insights into so-called structure–activity relationships, while nanoparticle systems have extended this knowledge toward industrial electrocatalysts. Yet, translating these insights into practical electrodes remains limited by the use of binders, supports, and surfactants, which mask active sites, compromise stability, and hinder reproducibility. This review provides a framework for the electrochemical restructuring of metal electrodes, emphasizing how electrochemical processes can generate nanostructured, binder-free, free-standing electrodes with tailored surface architectures. We critically evaluate restructuring strategies, including electrodeposition, potential cycling, anodic polarization, electrochemical dealloying, and particularly cathodic corrosion, reframing the latter not only as a degradation pathway but also as a versatile tool for fine-tuning metal surfaces and fabricating flexible electrodes. ... mehrFundamental insights into cathodic corrosion are discussed in detail, linking atomic-scale restructuring mechanisms with the emergence of features relevant for catalysis and electrocatalysis. We further address stability challenges, parameters influencing restructuring, and applications in electrocatalysis, including HER and OER, CO$_2$ reduction, nitrate reduction, and electro-oxidation of small organic molecules as candidates for fuels in energy storage and conversion. This review bridges electrochemical surface science with engineering of electrode materials to provide a roadmap for advancing surface design in energy technology, electrochemical science, and sustainable catalysis.