Electrochemical CO 2 Reduction in the Presence of Impurities: Influences and Mitigation Strategies.

The electrochemical conversion of waste CO 2 into useful fuels and chemical products is a promising approach to reduce CO 2 emissions; however, several challenges still remain to be addressed. Thus far, most CO 2 reduction studies use pure CO 2 as the gas reactant, but CO 2 emissions typically contain a number of gas impurities, such as nitrogen oxides, oxygen gas, and sulfur oxides. Gas impurities in CO 2 can pose a significant obstacle for efficient CO 2 electrolysis because they can influence the reaction and catalyst. This Minireview highlights early examples of CO 2 reduction studies using mixed-gas feeds, explores strategies to sustain CO 2 reduction in the presence of gas impurities, and discusses their implications for future progress in this emerging field.