Electrochemical Reduction of CO(2) to CO over Transition Metal/N‐Doped Carbon Catalysts: The Active Sites and Reaction Mechanism

Electrochemical CO(2) reduction to value‐added chemicals/fuels provides a promising way to mitigate CO(2) emission and alleviate energy shortage. CO(2)‐to‐CO conversion involves only two‐electron/proton transfer and thus is kinetically fast. Among the various developed CO(2)‐to‐CO reduction electrocatalysts, transition metal/N‐doped carbon (M‐N‐C) catalysts are attractive due to their low cost and high activity. In this work, recent progress on the development of M‐N‐C catalysts for electrochemical CO(2)‐to‐CO conversion is reviewed in detail. The regulation of the active sites in M‐N‐C catalysts and their related adjustable electrocatalytic CO(2) reduction performance is discussed. A visual performance comparison of M‐N‐C catalysts for CO(2) reduction reaction (CO(2)RR) reported over the recent years is given, which suggests that Ni and Fe‐N‐C catalysts are the most promising candidates for large‐scale reduction of CO(2) to produce CO. Finally, outlooks and challenges are proposed for future research of CO(2)‐to‐CO conversion.