Nickel single-atom catalysts intrinsically promoted by fast pyrolysis for selective electroreduction of CO2 into CO

The electrochemical reduction reaction of carbon dioxide (CO₂RR) is an effective way towards carbon neutralization. Single-atom catalysts (SACs) are expected to be efficient for CO₂RR  due to maximum atom utilization and excellent catalytic performance.  Here, nitrogen-doped carbon supported Ni SACs (Ni-SAC@NCs) were prepared  through effective fast pyrolysis. CO₂ can convert into CO efficiently with Ni-SAC@NCs as electrocatalysts for CO₂RR.  The faradaic efficiency kept well above 80% in the applied potential  window of −0.6 to −0.9 V (vs. reversible hydrogen electrode (RHE)), with  a highest FE_CO of 95% at −0.6 V (vs. RHE). Ni-SAC@NCs can  achieve the best CO selectivity under a small overpotential, surpassing  most other state-of-the-art catalysts. Computations also indicate that  the unique defect-Ni-N₃ structure is the active site. This  work not only provides a simple and promising new route for the  preparation of SACs, but also proves the key role of the coordination  environment in electrocatalysis.