Talk by Francesc Valls Mascaró

Abstract

Electrochemical X-ray Photoelectron Spectroscopy (EC-XPS) has emerged as a powerful tool to bridge the gap between surface science and electrochemistry, providing remarkable in situ insights into the chemical identity of the electrode-electrolyte interface under potential control. However, these measurements remain challenging due to the physics governing liquid-vacuum boundaries. In this presentation, we outline the architecture of our home-built EC-XPS setup and systematically break down the critical technical obstacles, as well as our subsequent solutions, encountered along the way [1].

With a robust experimental framework established, we apply this technique to a sequence of electrochemically diverse systems, ranging from powder electrocatalysts such as tungsten carbide [2], to polycrystalline substrates [1], and ultimately to well-defined single crystals such as Au(111) and Pt(111). Finally, we discuss the electrochemical shift — the potential-dependent variation of core-level binding energies. Using the O1s spectra of liquid water as an example, we demonstrate that the ideal 1 eV/V linear electrostatic shift is a universal phenomenon that persists across diverse substrates and electrolytes.

References

[1] C. Griesser, et al., Electrochem. Sci. Adv., 4, e2300007 (2023).

[2] C. Griesser, et al., Angew. Chem. Int. Ed., 64, e202500965 (2025).

 

About the speaker

Francesc Valls Mascaro
Department of Physical Chemistry, University of Innsbruck (Austria)