Lattice Anion Redox in Perovskite Oxides under Oxygen Evolution Conditions

Oxygen evolution reaction causes structural transformations and metal dissolution in most oxide electrocatalysts. In my talk, I will discuss how oxidative conditions cause intercalation of O^2- and can lead to the formation of oxidized oxygen inside the crystal lattice. Detection of anion oxidation is notoriously challenging and its unambiguous detection in electrocatalysts has been elusive so far. In our work, we used high-resolution resonant inelastic X-ray scattering (RIXS) to detect the oxidation state of oxygen in perovskites after OER, employing single-crystalline materials as model electrocatalysts. I will show that the emergence of oxidized oxygen depends on the transition metal and the amount of intercalation oxygen. In the end, I will discuss the possible relationship between lattice oxygen oxidation and the degradation of perovskite electrocatalysts during OER.