In operando study of structural and strain effects in iridium-ruthenium-based catalyst for the anode of the proton exchange membrane water e

Finding a sufficiently active, stable, and inexpensive catalyst for the anode side of the proton exchange membrane water electrolyzer (PEM-WE) remains one of the most principal obstacles preventing wider implementation of the concept of Hydrogen economy. Nanostructured Ir-Ru catalysts, containing less than 30 % of expensive Ir, are the possible industrially applicable solution to the problem. The effect of enhanced stability of inexpensive Ru by a small amount of Ir is known, yet still not comprehensively explained. The aim of this high-energy X-ray scattering experiment is to elucidate the complex concentration-dependent interplay between Ir and Ru, which affects the alloy´s structure, strain and chemical state and is most likely responsible for its high performance. Low-loading catalytic layers, prepared by magnetron co-sputtering, will be probed in operando as part of a functional membrane electrode assembly (MEA) within the recently commissioned WAXS/SAXS-compatible PEM-WE cell.