Metal-nitrogen-carbon catalysts for electrochemical CO reduction: from design to industrial applications.

The electrochemical CO reduction reaction (eCORR) offers a promising route for converting CO into value-added chemicals and fuels using renewable electricity. Developing efficient, stable, and scalable catalysts is key to advancing this technology for commercialization. As non-precious metal catalysts, transition metal-nitrogen-doped carbon (M-N-C) materials have demonstrated excellent catalytic performance due to their tunable electronic structure, high activity, and structural stability. Herein, we provide a comprehensive overview of our group's work in designing and optimizing M-N-C catalysts for the eCORR, focusing on metal site engineering, carbon substrate modification, and heteroatom doping strategies to enhance electrocatalytic efficiency and selectivity. We have also discussed the challenges and progress in scaling up the synthesis of M-N-C catalysts, integrating M-N-C materials into membrane electrode assembly (MEA) electrolyzers, and employing tandem electrocatalytic systems to achieve multi-carbon products. Comparisons between tandem catalysts and tandem electrolyzers based on M-N-C materials are presented. The potential of coupling the eCORR with thermocatalysis for producing other high-value products is also briefly discussed in this review. We envision that the M-N-C catalyst-based eCORR will offer a viable pathway for cost-effective CO utilization, while future research may focus on demonstrating long-term stability in large-scale electrolyzers and the development of efficient tandem reactor systems to further validate the commercialization potential.