Progress and Perspective of Direct Utilization of Flue Gas for Electrochemical CO₂ Reduction

Electrochemical carbon dioxide reduction reaction (CO₂RR) can convert CO₂ into high-value chemicals and fuels, which not only offers a promising way to store the intermittent renewable electricity but also contributes to achieving carbon neutrality. Nevertheless, present-day CO₂RR mainly relies on the use of high-purity CO₂ as the feedstock, while sourcing CO₂ from industrial flue gas requires additional costs for carbon capture and purification. Direct utilization of flue gas as feed for CO₂RR presents a highly impressive perspective but is hampered by substantial barriers. In this review, we first elucidate the key challenges of direct flue gas conversion, including the complex gas composition, impurity poisoning effects, and critical carbon loss in neutral/alkaline electrolytes. Advanced catalyst design strategies that are aimed specifically at enhancing the conversion efficiency under low CO₂ concentration, suppressing the competitive oxygen reduction reaction, and alleviating the SO_X/NO_X interference are then presented. Moreover, innovative routes for the co-electrolysis of CO₂ with impurity gases are also discussed. This review is ended by elaborating on the forward-looking perspectives and key development directions in this exciting research field.