Another important focus of our research is the investigation of iron-based catalysts. The aim is to further develop the fundamental understanding of the surface chemistry of iron catalysts under both oxygen-containing and oxygen-free reaction conditions. The reactions taking place in the presence of O₂ primarily include applications in the field of exhaust gas catalysis, in particular N₂O dissociation and NO_x reduction (selective catalytic reduction, SCR) as well as the oxidation of NO, NH₃, CO, HC and soot. The reactions in the absence of O₂ cover the synthesis gas chemistry including the CO₂ methanation, methanol synthesis, NH₃ synthesis and Fischer-Tropsch synthesis.