Unveiling the Mechanism of CO2 Reduction on Iron Sulphides Using Grazing Incidence X-ray Absorption Spectroscopy

The goal of this proposal is to perform operando XAS measurements on iron sulphides to investigate the oxidation state modification when employed as electrodes for electrochemical CO2 reduction. This research is set within the broader context of exploring the origins of life on Earth, where Fe-S is believed to have played a key role by facilitating the conversion of CO₂ and H₂ into the earliest organic molecules in alkaline hydrothermal environments. Utilizing a sutable spectro-electrochemical cell, we will electrodeposit the material onto the working electrode, modify the electrolyte composition, apply polarization and collect grazing incidence operando XAS spectra. By adjusting the electrolyte pH, composition and dissolved gas (CO2 or N2), we can examine the material’s oxidation state as it undergoes electrochemical oxidation and reduction. These findings will enhance our understanding of CO₂ valorization using non-noble metals, with clear implications for potential applications.