In situ Raman spectroscopic studies of CO2 reduction reactions: from catalyst surface structures to reaction mechanisms

Abstract

The electrochemical CO₂ reduction reaction (eCO₂RR) has gained widespread attention as an important technology for carbon cycling and sustainable chemistry. In situ Raman spectroscopy, due to its molecular structure, sensitive advantage and real-time monitoring capability, has become an effective tool for studying the reaction mechanisms and structure–performance relationships in eCO₂RR. This article reviews recent advancements in the application of in situ Raman spectroscopy in eCO₂RR research, focusing on its critical role in monitoring reaction intermediates, analyzing catalyst surface states, and optimizing catalyst design. Through systematic studies of different catalysts and reaction conditions, in situ Raman spectroscopy has revealed the formation and transformation pathways of various intermediates, deeply exploring their relationship with the active sites of the catalysts. Furthermore, the review discusses the integration of in situ Raman spectroscopy with other characterization techniques to achieve a more comprehensive understanding of the reaction mechanisms. Finally, we summarize the current challenges and opportunities in this research area and look ahead to the future applications of in situ Raman spectroscopy in the field of eCO₂RR.