Proceedings of MATSUS Spring 2025 Conference (MATSUSSpring25)
DOI: https://doi.org/10.29363/nanoge.matsusspring.2025.395
Publication date: 16th December 2024
Molecular electrochemistry has been complemented for several decades by spectroscopic measurements performed under in situ conditions, a method known as spectroelectrochemistry. Several spectroscopic techniques have been used in this configuration to provide structural insight in the understanding of molecular reactions mechanisms. In this talk, we will present how X-ray absorption spectroscopy, a synchrotron-based technique, can be instrumental in determining the local and electronic structure of electrochemically generated molecular species.
We will focus on the particular case of iron porphyrins, which are very efficient catalysts for the electrochemical reduction of CO2 into CO.1 We will first present a spectroelectrochemical cell specifically designed for the study of homogeneous molecular species generated electrochemically, together with a dedicated chamber for X-ray spectroscopic experiments. We will then present and analyze the X-ray absorption spectra collected on the starting Fe(III) species and its counterparts reduced by one, two or three electrons. Comparing the data collected under argon or CO2 will provide clues on the interactions between this substrate and the metal center, as well as on the CO2 reduction mechanism.2 Finally, we will discuss the possibility to perform similar experiments with time-resolution on electrochemically generated molecular species.