The Fritz Haber Institute (FHI) of the Max Planck Society is a place of interdisciplinary research at the intersection of chemistry, physics and material science. Most interaction with an environment happens at the boundary of matter, and it is this interaction that critically governs properties and function in many applications. As small details on the atomic scale have a sensitive influence on this, the main goal of research at the FHI lies in the precise study of how boundaries between two different matters behave and how key processes occur at these boundaries under various conditions. This is carried out with atomic precision, e.g. at the institute’s own free electron laser facility. Research at the institute covers the entire range from fundamental studies to applications in as important areas as catalysis, sustainable energy conversion (e.g. to green hydrogen or synthetic fuels) or nanoelectronics. A major current theme covers liquefied interfaces, ranging from properties of solvated molecules over electrochemical processes at electrodes to aerosol chemistry.