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

Abstract

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 FECO 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.