Surface science is "where the rubber hits the road". All materials have surfaces, and like a tire that grips or slips depending on its surface properties, a material's surface properties (mechanical, optical, magnetic, electronic, and chemical) determine how it interacts with the outside world. Chemical surface behavior in particular is central to a wide variety of technologies, including the catalytic converters used in cars.

Die Wechselwirkung von Atomen und Molekülen mit Oberflächen bestimmt eine Grosszahl von Prozessen in unserer Umgebung und in technologischen und chemischen Prozessen. Um die Wechselwirkung von Molekülen mit Oberflächen zu untersuchen, müssen die wenigen Atome und Moleküle, die mit der Oberfläche in Kontakt sind, von der sehr viel größeren Zahl der passiven Atome im Inneren des Materials getrennt werden. Resonante inelastische Röntgenstreuung (RIXS) und Nahkanten-Röntgenabsorptionsspektroskopie (NEXAFS) als elementspezifische und chemisch selektive Untersuchungsmethoden erlauben dies.

Deep within an ideal crystalline solid, every atom has a full complement of neighboring atoms, held in place by chemical bonds in all three dimensions. In contrast, atoms on the two-dimensional surface remain partially unattached, leaving "unsaturated" bonds that are available for chemical reactions with external substances. An understanding of how simple molecules bond to such surfaces is important for many different fields of science, including heterogenous catalysis, electrochemistry, biomaterials, and molecular environmental science. The basic questions are how molecules bond to sites with a particular geometry, or how i.e. metals and semiconductors differ with regard to their surface properties.  X-ray emission spectroscopy in combination with ab initio electron density calculations have an unique potential to explore the subtle interplay between the electronic and geometric structure of adsorbates. Carbon monoxide (CO) is known for its ability to populate different adsorption sites, depending on the substrate, CO coverage, temperature, and influence from coadsorbate species.