Ni single-atom arrays as self-supported electrocatalysts for CO2RR

Developing highly active, selective, and stable electrocatalysts for the CO 2 reduction reaction (CO 2 RR) is essential to relieve the greenhouse effect and the energy crisis. Traditional catalytic electrodes require ionomer binders, which inevitably impose undesired high CO 2 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 CO 2 RR. 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 CO 2 RR 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 CO 2 RR electrocatalysts by constructing ionomer-free electrodes.