Metal-Support Interactions on Iridium-based Catalysts for electrochemical Water Electrolysis probed by operando QuickXAS

Our goal is to provide deeper insights into the MSI of Ir NPs deposited on highly graphitized C and TiO2 during OER conditions and to correlate this information with the resulting catalytic activities. Operando electrochemical QuickXAS studies enable us to identify dynamic behavior of the nature of Ir oxide species and its electronic and geometric interactions (oxidation state, local environment) on two different support materials (MSI) as a function of the applied potential (before, during and after OER). In a two-step synthetic route, Ir NPs will be prepared by a colloidal approach and then immobilized either on the carbon or TiO2 support material. From XAS data recorded at Ir LII/LIII-edges, linear combination fit and EXAFS analysis will be carried out to understand the potential-resolved dynamic behavior of the chemical state of the Ir NPs (2-4 nm) and the nature of catalytically active oxide phase before, during and after the OER.