To reduce the carbon footprint of modern economy, using hydrogen as an energy medium is an important step. To achieve this, efficient ways to generate hydrogen with electric power have to be found. BAM, in close cooperation with other research institutes and the Technical University Berlin, is aiming at optimizing electrocatalysts for the electrolytic splitting of water in the HyMet-Consortium. In this technology, oxides of platinum metals like iridium oxide are of special interest. To improve the effiency of these catalysts, they have a porous structure. This imposes a considerable challenge for measurement methods suitable for their characterization as the porous and electronic properties of the oxideare to be determined nonindestructively at the same time. A well suited method to achieve this goal is spectroscopic ellipsometry, measuring the change of the polarization state of light upon reflection Ellipsometry is based on the modelling analysis of measured data. Therefore, the models used in the analysis must be improved constantly. If successful, this enables ellipsometry to be a key technology bridging the high accuracy and traceability of other methods into the field of application. Therefore, BAM uses Hybrid Metrology to connect ellipsometry with such methods as electron microscopy, mass spectrometry, X-ray analysis, X-ray reflectometry, and crystallography.This work then provides a better understanding of these materials required to obtain optimized materials in the future.
Assessing optical and electrical properties of highly active IrOx catalysts for the electrochemical oxygen evolution reaction via spectroscopic ellipsometry
René Sachse, Mika Pfüger, Juan-Jesús Velasco-Vélez, Mario Sahre, Jörg Radnik, Michael Bernicke, Denis Bernsmeier, Vasile-Dan Hodoroaba, Michael Krumrey, Peter Strasser, Ralph Kraehnert, Andreas Hertwig
published in ACS Catalysis, pages 14210-14223, 2020
BAM Division Surface Modification and Measurement Technology
and Division Surface Analysis and Interfacial Chemistry