The suggested projects' main goals are to investigate the magnetron-sputtered iridium-ruthenium-based catalysts employing X-ray diffraction at the European Synchrotron Radiation Facility (ESRF) in Grenoble. We intend to build on our previous results, where we showed that Ir:Ru 1:3 alloy is more active than Ir:Ru 1:1. The analysis by X-ray Photoelectron Spectroscopy (XPS), Scanning Electron Microscopy (SEM), and Energy Dispersive X-ray spectroscopy (EDX) unraveled that the improved electrochemical activity might be due to the chemical and structural state. However, to fully understand the proposed phenomena more advanced techniques have to be employed. The analysis carried out in Prague was done post-mortem, i.e. after the electrochemical procedures, while the local team of Dr. Drnec has a unique experimental setup that would allow us to measure the structural effects in operando, i.e., during an actual operation of the PEM-WE in a dedicated operando cell. This approach appears to be very useful as it is expected that the enhanced activity of the iridium-ruthenium-based catalyst is strongly connected to the charge transfer due to the interaction between iridium, ruthenium, and adsorbed reactants or products. Since the changes in the charge distribution are often associated with the structural strain, the X-Ray diffraction appears to be suitable for this study. The formation of strain in studied nanostructured material is most likely potential induced, which means that other than operando methods do not allow to fully observe and comprehend it. Additional goals consist of the improved collaboration between the group of Dr. Drnec (ESRF) and Dr. Kúš (Charles University) and the possibility of studying surface physics from the top scientist at ESRF. The main output will be a joined publication between both groups which should uncover the investigated phenomenon.