The experimental setup presented in this work combining laboratory-based X-ray absorption spectroscopy with an electrochemical reactor advances the fundamental understanding of electrocatalysts at extended time scales. By the example of the electrochemical reduction of CO₂, the parameters are discussed that are relevant for optimizing the system to achieve high-quality extended X-ray absorption fine structure data measured under operando conditions.

The field of electrocatalysis can play a transformative role in the utilization of renewable electricity and the sustainable production of value-added products. However, to enhance the performance and drive the industrial applicability, the electrocatalysts’ properties and their evolution need to be thoroughly understood and characterized under relevant working conditions and at industrially relevant time-scales. Laboratory-based X-ray absorption spectrometers are promising devices for accessible catalyst characterization, enabling X-ray absorption spectroscopy (XAS) experiments that are not compatible with the traditional synchrotron beamtime access mode. In particular, they allow the screening of a large number of catalysts or experimental parameters and also long-term studies of catalysts’ (de-)activation processes. Here, the feasibility of carrying out laboratory-based in situ and operando XAS studies in combination with electrocatalytic studies at solid–liquid interfaces are demonstrated. In particular, the challenges and possibilities are discussed for tracking the electronic and structural transformations in electrocatalysts with a laboratory-based spectrometer operated in transmission and fluorescence modes. The methodologies presented here will accelerate catalyst development by providing easier access to in situ and operando XAS and will pave the way for new experiment designs and durability studies.