A brief review of in situ spectroscopic methods and electrochemical sensors as essential evaluation tools for the electrochemical reduction of CO2 (ElRC)

Electrochemical reduction of CO2 (ElRC) is a practical method for storing energy from renewable sources while completing the carbon cycle. Presently, electrochemical conversion energy technologies, which are more environmentally friendly alternatives to traditional fossil fuel-based systems, are dependent on electrocatalysis. However, although there have been substantial improvements in the fabrication of new electrocatalysts, these systems still lack the necessary energy conversion efficiency to be appropriate technology for application in industry. Electrocatalysts need to be economical, extremely efficient in reducing CO2, resistant to deactivation, and highly conductive to minimizing the requisite overpotential. Understanding the precise reaction mechanism and structural changes during the reaction environment is necessary for developing active and selective electrocatalysts for enhanced energy conversion efficiency. In situ spectroscopic and electrochemical sensors are among the most effective means to study a system in its real environment. Spectroscopic investigations of the interface (electrode electrolyte) may be possible to better comprehend the morphological and compositional aberrations that take place during the course of an electrochemical reaction. Electrochemical sensors offer an affordable and effective method for identifying a range of analytes in a reaction and are widely used because they can provide a variety of signals, including current, voltage, electrochemical impedance and total power output together with low theoretical detection due to the disparities between faradaic and non-faradaic currents. The present review provides an effort for the first time to address the recent developments and usage of both spectroscopic methods and electrochemical sensors as assessment tools for ElRC.