Substrate‐Driven Catalyst Reducibility for Oxygen Evolution and Its Effect on the Operation of Proton Exchange Membrane Water Electrolyzers

To increase the efficiency of hydrogen production by proton exchange membrane water electrolyzers (PEMWEs), relationships between specific activity and stability membrane–electrode assembly (MEA) must be clarified. Ir oxide electrodeposited on Ti substrate is used as an oxygen electrode, its electronic properties electrochemical behavior in PEMWE operation are observed. The fabricated through a facile strategy based annealing air atmosphere, enhances evolution reaction (OER) operation. Furthermore, catalyst–substrate interactions associated with different reducibilities heteroatom system studied. morphology, properties, chemical state electrode investigated X‐ray spectroscopy, microscopy techniques, computational analyses. Thermal treatment catalyst‐coated decreases bulk oxidation increases surface state. According to physical analyses PEMWEs, content structure, which defines OER stability, influenced crystalline structure formation stable interface catalyst substrate. outcomes can facilitate development strategies for enhancing performance PEMWEs designing rational MEAs.