(532ab) Understanding the Mechanism of C-N Coupling in Electrochemical CO2 Reduction on Metal Surfaces

Carbon neutrality is essential for achieving sustainable development of human societies. Among various technologies of carbon conversion, electrochemical CO₂ reduction has drawn attention since it has the potential to solve the greenhouse gas issue and potentially store the intermittent renewable energy to chemicals. The state-of-the-art electrocatalytic CO₂ reduction usually produces a variety of carbon-based products. However, it’s hard to further increase the value and expand the scope of products which is limited by solely employing CO₂ and H₂O as reactants. The integration of N into the electrochemical CO₂ reduction could offer valuable products including organonitrogen compounds when considering the bond-forming between carbon and nitrogen. The C-N coupling induced electrochemical CO₂ reduction is environmentally and economically beneficial since it could yield organonitrogen compounds which are normally sourced from NH3 industrially produced by the energy extensive Haber-Bosch process. Nonetheless, the complicated reaction mechanism of C-N coupling in CO₂ reduction remains elusive due to the multistep kinetics and unclear C-N coupling intermediates. Supported by in-situ experimental measurements and characterizations, we performed theoretical studies to unravel the mechanism of C-N coupling in electrocatalytic CO₂ reduction starting from CO₂ and NO₃^- reactants on metal surfaces. By employing the chemisorption and machine learning (ML) models, we also performed the rational design for catalysts candidates that show promising performance, which opens a new path for catalytic materials discovery for organonitrogen compound production.