Data underlying the publication: Laboratory-based in situ and operando tri-color X-ray photoelectron spectroscopy

Innovative approaches to study buried interfaces and heterogenous interactions under reaction conditions are crucial for advancing energy and catalytic materials. Our Near-Ambient Pressure X-ray Photoelectron Spectroscopy (NAP-XPS) setup is equipped with a novel tri-color X-ray source, with Al Kα, Ag Lα, and Cr Kα excitation energies, enabling information depth-selective operando and in situ analysis of solid-liquid, solid-gas, and solid-solid interfaces. We present three case studies to demonstrate the systems’ capabilities. First, we compare experimental depth profiling of a LaMnO3/LaFeO3/Nb:SrTiO3 multilayer with SESSA simulations. Second, we examine the oxidation and reduction of FexOy as a function of environment and temperature. Finally, the Pt/liquid electrolyte interface is examined, revealing surface oxidation in the absence of bulk oxidation. As our results confirm, the unique combination of a NAP-XPS with the novel tri-color X-ray source empowers laboratory-based in situ and operando XPS characterization of advanced materials under reaction conditions in a wide range of applications.