Electrochemical CO2 Reduction in the Presence of Impurities: Influences and Mitigation Strategies.

The electrochemical conversion of waste CO2 into useful fuels and chemical products is a promising approach to reduce CO2 emissions; however, several challenges still remain to be addressed. Thus far, most CO2 reduction studies use pure CO2 as the gas reactant, but CO2 emissions typically contain a number of gas impurities, such as nitrogen oxides, oxygen gas, and sulfur oxides. Gas impurities in CO2 can pose a significant obstacle for efficient CO2 electrolysis because they can influence the reaction and catalyst. This Minireview highlights early examples of CO2 reduction studies using mixed-gas feeds, explores strategies to sustain CO2 reduction in the presence of gas impurities, and discusses their implications for future progress in this emerging field.