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.