Our research focuses on interface science, where we investigate the properties of two adjacent condensed phases. Such properties are important in material science, energy conversion and storage, catalysis and electrocatalysis and for medical applications. In all these areas, nanostructures play a crucial role. We fabricate nanostructured surfaces and characterize them in terms of their catalytic activity and their use in the respective applications. A new bottom-up approach, relying on a separation of the physical parameters, is used to study innovative and promising catalyst systems. We employ scanning probe microscopy, electrochemical techniques, and surface analysis tools for detailed investigation of the systems.