In Situ Spectroscopy in Electrochemical Reduction of Carbon Dioxide

With the continuous consumption of fossil energy, the global environment faces severe problems such as energy consumption, climate change, and the intensification of the greenhouse effect. Whereas, carbon dioxide electrochemical reduction (CO2RR) can transform CO2 into fuels and chemicals of high value via catalytic processes, and the conditions are mild, and the reaction is controllable, environmentally friendly, and there are many products. As a result, CO2RR technology has become a promising way to address these problems and achieve sustainable development. Nonetheless, the inadequate comprehension of the electrocatalytic kinetic mechanism continues to impede the logical creation of these electrocatalysts. Utilizing in situ infrared spectroscopy, Raman spectroscopy, and X-ray absorption spectroscopy proves highly effective for comprehensively grasping the dynamic dynamics of molecular electrocatalytic reactions. This knowledge aids in uncovering the mechanisms behind reactions, including the strength of the binding bond, variations in atomic vibration peaks, and shifts in valence. According to the spectroscopic principle of obtaining catalyst surface information, each in situ operation technology derives different detection methods, suitable for various materials and forms of catalysts. This review summarizes recent advances in the fields of in situ infrared spectroscopy, in situ Raman spectroscopy, and in situ X-ray absorption spectroscopy. Finally, the difficulties and prospects in CO2RR research are discussed.