Boosting CO2 electroreduction to CO with abundant nickel single atom active sites

Abstract

The conversion of CO₂ into value-added chemicals through the electrocatalytic CO₂ reduction reaction (CO₂RR) is considered as an up-and-coming way to facilitate the renewable closed carbon cycle and energy storage. Therefore, the development of robust and low-cost CO₂RR electrocatalysts is essential but challenging. Herein, a Ni single-atom catalyst (Ni–SAs–NC) was successfully prepared via a precursor assembly strategy and a subsequent one-step pyrolysis process. Characterization studies demonstrate that abundant Ni single-atom active sites with the coordination structure of Ni–N₄ are uniformly dispersed in Ni–SAs–NC, which consequently endow it with outstanding electrocatalytic CO₂RR performance. Strikingly, the as-prepared Ni–SAs–NC can selectively convert CO₂ into CO with a high faradaic efficiency of up to 98%, and can maintain the high values exceeding 90% in a wide potential range from −0.6 to −1.0 V. This work provides a new protocol to prepare high-efficiency but low-cost single-atom electrocatalysts toward the CO₂RR and other electrochemical reactions.