Molecular Nitrogen–Carbon Catalysts, Solid Metal Organic Framework Catalysts, and Solid Metal/Nitrogen‐Doped Carbon (MNC) Catalysts for the Electrochemical CO₂ Reduction

Abstract The CO₂ electrochemical reduction reaction (CO2RR) is a promising technology for converting CO₂ into chemicals and fuels, using surplus electricity from renewable sources. The technological viability of this process, however, is contingent on finding affordable and efficient catalysts. A range of materials containing abundant elements, such as N, C, and non‐noble metals, ranging from well‐defined immobilized complexes to doped carbon materials have emerged as a promising alternative. One of the main products of the CO2RR is CO, which is produced on these catalysts with selectivities comparable to those of noble metal catalysts. Furthermore, other valuable products, such as formic acid, hydrocarbons, and alcohols, have also been reported. The factors that control the catalytic performance of these materials, however, are not yet fully understood. A review of recent work is presented on heterogeneous nitrogen‐containing carbon catalysts for the CO2RR. The synthesis and characterization of these materials as well as their electrocatalytic performance are discussed. Combined experimental and theoretical studies are included to bring insight on the active sites and the reaction mechanism. This knowledge is key for developing optimal catalyst materials that meet the requirement in terms of activity, selectivity, and stability needed for commercial applications.