TES detection pushes the powerful soft X-ray spectroscopic tools (XAS, XES, RIXS) to world leading impurity level characterization and unprecedented low concentration systems. Scientific focus is on catalytic active sites, nucleation processes and materials impurities and doping levels. The superconducting bolometer principle achieves energy resolved single photon detection. This yields unsurpassed performance for excited molecules, active sites, catalytic thin films and nanostructes but also properties such as spin-flip scattering processes in low-dimensional and dilute systems. MPI-CEC as partner forms a bridge to CatLab: The highest-level characterization possibilities of a TES at a high flux beamline with full polarization control is a real asset for the development of novel catalyst systems. Uniqueness: The investigation by XAS, XES and RIXS with full polarization control of systems with minute amount materials in solids and liquids will be unique at BESSY II. Partners: MPI-CEC, HZB
