Dataset of "Design and Operation of a Versatile Operando Electrochemical XPS Platform for Aqueous Electrocatalysis"

Understanding electrocatalyst activation and degradation under realistic operating conditions requires operando spectroscopic techniques capable of probing solid-liquid interfaces with running electrochemistry. Here, we present the design and implementation of a versatile operando electrochemical XPS platform compatible with aqueous environments and controlled current or potential operation. The modular cell architecture enables both conventional three-electrode half-cell measurements and zero-gap proton-exchange membrane or anion-exchange membrane water electrolysis at industrially relevant current densities. Key design considerations, including electrolyte management, membrane integration, gas handling, electrical isolation, and X-ray access geometry, are discussed in detail. The platform allows investigation of catalyst oxidation, hydroxylation, and surface restructuring under realistic electrochemical conditions. Representative measurements demonstrate stable operation during high-current water electrolysis as well as flexibility for broader electrocatalytic studies. This protocol provides a practical framework for implementing operando XPS in electrochemical research laboratories and facilitates reproducible investigation of dynamic catalyst transformations at electrified interfaces.