In order to develop our society towards a sustainable and closed cycle economy, electrochemical technologies and processes, such as hydrogen production, fuel cells, batteries, recycling and their further development in terms of energy efficiency, life time and corrosion protection play a key role.

All these technologies involve nanoscale interfacial processes whose understanding is of utmost importance for further development.

Ultra-high vacuum (UHV) methods from the field of surface analysis are used for this purpose, especially in the area of basic research, as they enable comprehensive chemical and topographic analyses of surfaces and interfaces with nanoscale resolution.

In order to improve electrochemical systems with practical relevance, complex electrochemical individual reactors have to be built, which ideally are directly connected to the UHV system and/or systems that allow electrode transfer without air contact. This is realized in the "Electrochemical surface and interface analysis cluster (ELSA)" initiated by CEST in collaboration with TU Wien, in which two complementary high-resolution UHV techniques, the X-ray Photo- and the Auger-Electron-Spectroscopy, are combined with the reactors and transfer systems important for electrochemical applications, thus bridging the gap between basic and application-oriented research.