(Invited) Probing Oxygen Intercalation, Oxidation and Chemo-Mechanical Coupling in OER Electrocatalysts

I will discuss how intercalation of O 2- under OER conditions can lead to lattice oxygen redox and chemo-mechanical coupling inside the crystal lattice of a perovskite electrocatalyst. Specifically, I will show that high-resolution resonant inelastic X-ray scattering (RIXS) can detect the oxidation state of oxygen in a perovskite oxide. The emergence of oxidized oxygen depends on the transition metal and the amount of intercalated oxygen. At the same time, oxygen dimerization has a direct relevance to the stress-induced structural disorder that takes place inside the electrocatalyst. At the end, I will also discuss our recent finding in which oxygen can intercalate spontaneously following a catalytic O 2 splitting at the surface and induce substantial transformations in the bulk of the perovskite.