Electrochemical impedance spectroscopy as a tool to investigate the electroreduction of carbon dioxide: A short review

Abstract Carbon dioxide electroreduction (CO2ER) exploited in conjugation with renewable energy sources can open the path to a carbon-neutral energy cycle, concurrently offering the possibility to synthesize low-carbon fuels. In the last decades, a huge amount of work has been carried out by the scientific community in order to obtain high-performing and low-cost catalysts, and to design reactors able to maximize the efficiency of CO2ER. Electrochemical impedance spectroscopy (EIS) proved to be a useful tool in studying this electrochemical reaction, and has been widely employed to characterize novel materials and reactor architectures. The aim of this Review is to provide an insight on the application of EIS for the study of CO2ER. A brief introduction on the technique and on the reaction will be given, followed by a review of the most important applications in this field. Finally, a brief discussion of future research directions will be presented.