Investigating the activation of In-Bi electrocatalyst during CO2 reduction to formate via a combination of in situ X-ray absorption spectros

Post transition metal-based electrocatalysts are known for the selective electroreduction of CO2 (CO2ER) to formate. The In-Bi catalyst, composed by alloys of Indium and Bismuth, shows great selectivity and stability (≈100% faradaic efficiency over 24 hours at ≈100mA/cm2) before deactivation. Understanding the activation mechanism is crucial for preventing deactivation. Literature suggests Indium to catalyse CO2ER via a metastable oxide layer, while the oxides role in Bismuth catalysts is unclear. Our preliminary X-ray diffraction (XRD) data on In-Bi samples suggest a de-alloying mechanism. We propose a combination of in situ X-ray absorption spectroscopy and XRD to reveal the role of oxides in the activation of the In-Bi electrocatalyst and to trace local environment and crystalline structure changes during catalysis. These insights will contribute to the scientific discussion on the mechanism of Indium and Bismuth in CO2ER, and to the industrial application of the In-Bi catalyst.