Dynamic Activation of Adsorbed Intermediates via Axial Traction for the Promoted Electrochemical CO₂ Reduction

Abstract

Regulating the local environment and structure of metal center coordinated by nitrogen ligands (M-N₄ ) to accelerate overall reaction dynamics of the electrochemical CO₂ reduction reaction (CO₂ RR) has attracted extensive attention. Herein, we develop an axial traction strategy to optimize the electronic structure of the M-N₄ moiety and construct atomically dispersed nickel sites coordinated with four nitrogen atoms and one axial oxygen atom, which are embedded within the carbon matrix (Ni-N₄ -O/C). The Ni-N₄ -O/C electrocatalyst exhibited excellent CO₂ RR performance with a maximum CO Faradic efficiency (FE) close to 100 % at -0.9 V. The CO FE could be maintained above 90 % in a wide range of potential window from -0.5 to -1.1 V. The superior CO₂ RR activity is due to the Ni-N₄ -O active moiety composed of a Ni-N₄ site with an additional oxygen atom that induces an axial traction effect.