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Developing highly active, selective, and stable electrocatalysts for the CO2 reduction reaction (CO2RR) is essential to relieve the greenhouse effect and the energy crisis. Traditional catalytic electrodes require ionomer binders, which inevitably impose undesired high CO2 transport resistance and block the active sites. Herein, Ni single atoms anchored on nitrogen‐doped carbon nanoarrays (denoted as Ni‐SAC‐NA) were developed as the electrode without additional ionomers for efficient CO2RR. The unique nanoarray structure provided a higher specific surface area, more exposed active sites, and enhanced electron/mass transport due to its short diffusion pathway and ionomer‐free nature. As a result, the Ni‐SAC‐NA electrode exhibited enhanced activity of CO2RR and selectivity towards CO with Faradaic efficiency of 96.7%, turnover frequency of 27,504 h−1, and cathodic energy efficiencies of 54.9% at −0.88 V (vs. RHE). Our findings provide a rational design strategy for CO2RR electrocatalysts by constructing ionomer‐free electrodes. [ABSTRACT FROM AUTHOR]

Single‐atom catalysts (SACs) show great promise for electrochemical CO2 reduction reaction (CRR), but the low density of active sites and the poor electrical conduction and mass transport of the single‐atom electrode greatly limit their performance. Herein, we prepared a nickel single‐atom electrode consisting of isolated, high‐density and low‐valent nickel(I) sites anchored on a self‐standing N‐doped carbon nanotube array with nickel–copper alloy encapsulation on a carbon‐fiber paper. The combination of single‐atom nickel(I) sites and self‐standing array structure gives rise to an excellent electrocatalytic CO2 reduction performance. The introduction of copper tunes the d‐band electron configuration and enhances the adsorption of hydrogen, which impedes the hydrogen evolution reaction. The single‐nickel‐atom electrode exhibits a specific current density of −32.87 mA cm−2 and turnover frequency of 1962 h−1 at a mild overpotential of 620 mV for CO formation with 97 % Faradic efficiency. [ABSTRACT FROM AUTHOR]

Single‐atom catalysts have drawn considerable attention because of their unique catalytic properties. However, the high surface energy of single atoms restricts their fabrication and creates significant challenges for further developments. In order to overcome this problem, metal organic framework (MOF)‐derived carbon materials can be served as ideal supports to anchor atomically dispersed metal atoms, due to their tunable particle size and shape features, by providing high surface area, porosity, thermal, and chemical stability. This review highlights the recent advances in i) different types of construction strategies for MOF‐derived carbon‐supported single‐atom catalysts, and ii) the catalytic applications of these MOF‐derived carbon‐supported single‐atom catalysts. Further, this review offers a valuable insight into the current challenges and future opportunities for MOF‐derived carbon‐supported single‐atom catalysts. [ABSTRACT FROM AUTHOR]