Regensburg 2025 – wissenschaftliches Programm
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MM: Fachverband Metall- und Materialphysik
MM 22: Materials for the Storage and Conversion of Energy
MM 22.4: Vortrag
Mittwoch, 19. März 2025, 16:30–16:45, H23
Assessing the Bulk Stability of Oxygen Evolution Reaction Catalysts using Crystal Field Theory and Orbital Analysis — •Katarina Kretschmer1, Michael Eikerling1,2, and Tobias Binninger1 — 1Theory and Computation of Energy Materials (IET-3), Institute of Energy Technologies, Forschungszentrum Jülich GmbH, 52425 Jülich, Germany — 2Chair of Theory and Computation of Energy Materials, Faculty of Georesources and Materials Engineering, RWTH Aachen University, 52072 Aachen, Germany
Proton exchange membrane water electrolysis (PEMWE) is an effective method for producing green, i.e. carbon-neutral hydrogen. At the PEMWE anode catalyst, water molecules are split to form oxygen molecules in the so-called oxygen evolution reaction (OER). Iridium oxide (IrO2) and ruthenium oxide (RuO2) are recognized as highly effective catalysts for the OER.
In this talk, I will discuss the electronic properties governing the bulk stability if IrO2 and RuO2. Utilizing density functional theory (DFT) calculations, the stability of both oxide materials is assessed from the perspective of crystal field theory and bond orbital analysis. The orbital overlap between the metal (iridium or ruthenium) and oxygen atoms in the lattice and the population of the emerging bonding or antibonding orbitals is analyzed, which can either contribute to or counteract the stability of the IrO2 and RuO2 lattices. This analysis will lead to the definition of electronic descriptors for predicting the bulk stability of transition metal oxide catalysts.
Keywords: catalyst; hydrogen; stability; anode; watersplitting