Electrochemical CO₂ Reduction Using Industrial Flue Gas Stream as Feedstocks: Recent Advances and Future Perspectives

Electrochemical CO₂ reduction (ECR) to value-added chemicals and fuels is a promising route to close the artificial carbon cycle. However, most current research relies on energy-intensive purified CO₂ streams, which is not economically or environmentally viable. Directly utilizing industrial flue gas, with low CO₂ partial pressure and complex impurities, is a more sustainable alternative but poses challenges of mass transfer limitations and catalyst poisoning. This review summarizes recent advances in directly electrolyzing dilute CO₂ feedstocks from industrial flue gas. We begin by elucidating the fundamental mechanisms and mass transfer challenges associated with low-pressure CO₂ reduction, where local CO₂ concentration and pH govern reaction pathways and product selectivity. Strategies to overcome mass transfer limitations, such as regulating CO₂ feed concentration, flow rate, system pressure, and rational catalyst design, are summarized. The review also analyzes the impacts of major flue gas impurities on catalytic activity, stability, and product selectivity, revealing both detrimental and occasional synergistic effects. Innovative catalyst designs, such as selectively permeable membranes, surface functionalization, hydrophilic nanochannel coating, core-shell architectures, electronic structure regulation, and adjusting local coordination environments for improving impurity tolerance are highlighted. Besides, the innovative process of co-electrolysis of impurities with CO₂ for collaborative utilization of resources is explored. Finally, future challenges and perspectives are outlined, emphasizing the need for multi-scale modeling, external field enhancement, pilot-scale demonstrations, and integrated techno-economic and life cycle assessments to accelerate the industrial implementation of direct flue gas electrolysis. This review aims to offer critical insights and guidance for developing efficient, stable, and economically feasible ECR systems for real-world industrial applications.