Scanning electron microscope with energy-dispersive X-ray spectroscopy (SEM/EDX)

• Subject Area: Process Engineering, Technical Chemistry
• Term: Funded in 2026
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 574292174

Subject of the project is a modern field emission scanning electron microscope with coupled energy dispersive X-ray spectroscopy (FE-SEM/EDX). This instrument is to be utilized at the Department of Chemistry at RPTU Kaiserslautern-Landau for the investigation of heterogeneous catalysts, porous materials, polymer composites, and particle technology. The device replaces a 20-year-old electron microscope that is no longer functional and was operated with tungsten or LaB6 cathodes. Compared to this technology, a Schottky field emitter has the capacity to attain considerably higher resolutions and exhibit exceptional analytical capabilities. Warm Schottky field emitters are distinguished by their relatively long service life, which spans several years, and they exhibit constant emitter properties. In comparison to cold field emitters, Schottky emitters have been demonstrated to exhibit a substantially higher beam current. The system can be used to determine the size distribution and morphology of catalyst particles, which is of great relevance for understanding reaction mechanisms in heterogeneous catalysis. The main device incorporates a high-performance EDX detector, a critical component for the analysis of elemental distribution in multi-metal catalysts within the nanometer range. To employ the EDX and the BSE detector effectively for measurements of poorly conducting samples (e.g., polymers or metal-organic frameworks), the device must also be capable of efficient operation in low-vacuum mode. Furthermore, the device is equipped with a segmented STEM detector, which facilitates the acquisition of high-contrast bright and dark field images (BF, DF, ADF, HAADF). The integration of these components fosters an exceptional analytical spatial resolution, which can be leveraged, for instance, to ascertain the spatial distribution of metals in core-shell systems. The integration of a transfer shuttle with the sample lock of the instrument allows the introduction of samples into the measuring chamber under inert conditions. Catalyst particles utilized in continuously operated laboratory reactors can be loaded into the transfer system in a glovebox for analysis without direct exposure to the laboratory environment. Consequently, it is feasible to assess the chemical composition of utilized catalysts directly after their catalytic application. The device is also equipped with a plasma cleaner, which is utilized to eliminate impurities and deposits in the analysis chamber. This ensures that the image and analysis quality remain at a high level throughout the system's entire service life. The device is operated as part of RPTU's "Imaging Center," which regulates access by other user groups.

• DFG Programme: Major Research Instrumentation
• Major Instrumentation: Rasterelektronenmikroskop mit energiedispersiver Röntgenspektroskopie (REM/EDX)
• Instrumentation Group: 5120 Rasterelektronenmikroskope (REM)
• Applicant Institution: Rheinland-Pfälzische Technische Universität Kaiserslautern-Landau
• Leader: Professor Dr. Wolfgang Kleist