X-ray absorption spectroscopy unit for the laboratory operation (LabXAS)

• Subject Area: Process Engineering, Technical Chemistry
• Term: since 2026
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 584872300

The characterization of functional materials requires a toolbox that allows characterization of amorphous and crystalline samples, the surface and the bulk as well as ex situ and in situ / operando (i.e. under working conditions). X-ray absorption spectroscopy (XAS) has become one of the key methods, generating element-specific insights into atomic and amorphous structures (oxidation state, particle size, coordination environment) also under reaction conditions. These studies are carried out at synchrotron facilities during a beamtime and after application with a proposal. However, in recent years, lab-based XAS has become viable enabling basic studies in a much shorter time loop in the home lab. Due to the limited time at synchrotron radiation sources, the complementary application of a LabXAS instrument presents a unique opportunity for fast feedback mainly by ex situ studies but also selected in situ experiments. This allows 1) to close the direct feedback loop to the materials synthesis, 2) to efficiently utilize research campaigns at synchrotron radiation facilities and 3) to train students and (doctoral) researchers in XAS-based experiments. The device will be a new analysis equipment for institutes at KIT particularly dealing with heterogeneous catalysis to element specifically analyse the structure with respect to their local structure and oxidation state. This information will be complementary to the insights achieved by X-ray diffraction (crystallinity), electron microscopy (local information), elemental analysis and synchrotron X-ray techniques (which can only be received in measurement campaigns). This is particularly important for analysing catalysts for emission control, power-to-chemicals/fuels or direct thermo/electrocatalytic H2O2 production. Thus, XAS serves as an essential feedback mechanism for the preparation of single atoms, supported clusters or particles, as well as other catalysts developed through novel preparation techniques. In addition, it is important for understanding energy storage cycles for metals used as “metal fuels”. It is closely connected to several ongoing and planned research initiatives at KIT. For these purposes, a sufficiently high energy resolution (close to 1 eV) has to be combined with a high photon efficiency. The LabXAS spectrometer will integrate X-ray tube source, high-resolution spectrometer, and X-ray detector together with a software suite to operate the device and analyse data. The X-ray tube source and spectrometer need to cover an energy range 4 to 25 keV, thus including the K absorption edges of 3d-transition metals and allowing to monitor many of the important catalytic elements. Strategically, the LabXAS unit will strengthen the research in catalysis and the diverse characterization options. The device is to be included in the local spectroscopy cluster for a fast feedback complementary to the activities at large scale facilities, which aim at operando studies on selected samples.

• DFG Programme: Major Research Instrumentation
• Major Instrumentation: Röntgenabsorptionsspektrometer für die Nutzung im Labor (LabXAS)
• Instrumentation Group: 4030 Röntgenfluoreszenz-Spektrometer
• Applicant Institution: Karlsruher Institut für Technologie
• Leader: Professor Dr. Jan-Dierk Grunwaldt