Metal-Nitrogen-doped carbon single-atom electrocatalysts for CO2 electroreduction

The application of the electrocatalytic CO2 reduction reaction (CO2RR) to high-value-added carbon items is an incredibly encouraging course for the mitigation of greenhouse gas emissions. However, the effective design of CO2RR electrocatalysts with high proficiency, great selectivity, and robust stability presents serious challenges. Electrocatalytic CO2RR involves complicated mechanisms due to multiple electron/proton transfer processes, resulting in various intermediates. To further understand the mechanism of CO2RR, single atomic site catalysts represent a simplified catalytic model which can also lead to improvements in catalytic activity. On account of the unique electronic and geometric structures, metal-nitrogen-doped carbon (M-N-C) single-atom electrocatalysts have energizing possibilities for the CO2RR, and are a potential substitute for noble metal catalysts. This review pays attention to the recent advancements of M-N-C catalysts for the CO2RR, which include the synthesis, characterization, and performance. Combining experimental and theoretical aspects, it is found that new insight is being achieved into the role of active sites on the reaction mechanism. Finally, approaches to the design of electrocatalysts for CO2RR and future research directions are discussed.