Electroreduction of CO₂: Advances in the Continuous Production of Formic Acid and Formate

Abstract

The study of the electrochemical CO2 reduction to obtain formate (HCOO–) or formic acid (HCOOH) is receiving much attention as a promising technology. Since continuous–mode operation has become necessary for practical implementation of electrochemical CO2 reduction, recent years have seen a rapid increase in the number of research approaches focusing on this aspect. This Focus Review provides a unified discussion of the available studies on the continuous electroreduction of CO2 to HCOO–/HCOOH, considering the different important features of process design. Moreover, this paper quantitatively assesses the performance of different studies that involve continuous electrochemical reactors for converting CO2 to HCOOH/HCOO–, comparing relevant typically used figures of merit, including energy consumption. Although some relevant trade-offs have already been achieved, the simultaneous optimization of all the figures of merit remains a challenge. Finally, concluding remarks highlight the detected trends and discuss relevant aspects that will have to be tackled by future studies in this field.