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 (CO2RR) 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 CO2RR 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 CO2RR 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.

Proton Capture Strategy for Enhancing Electrochemical CO2 Reduction on Atomically Dispersed Metal–Nitrogen Active Sites**

“…With intermediates of *COOH and *CO, their d‐states of valence band peaks decreased obviously that indicates the d‐states contribute to the intermediates transition from *CO 2 to *COOH, then to *CO. Meanwhile, these results could be well retained to show an excellent activity and stability for Ni@NiN 4 CM model during the catalytic reactions [26] . From Figure 5 d, it can be seen that the Ni NPs can assist to capture H 2 O and H ad , thus promoting the *CO 2 transition to *COOH on the Ni atom in NiN 4 structure.…”

“…These 1b, showing that the CO 2 and H 2 Omolecules are easily adsorbed on the active center physically.W ith intermediates of *COOH and *CO,t heir d-states of valence band peaks decreased obviously that indicates the d-states contribute to the intermediates transition from *CO 2 to *COOH, then to *CO.Meanwhile,these results could be well retained to show an excellent activity and stability for Ni@NiN 4 CM model during the catalytic reactions. [26] From Figure 5d,i tc an be seen that the Ni NPs can assist to capture H 2 Oand H ad ,thus promoting the *CO 2 transition to *COOH on the Ni atom in NiN 4 structure.Consequently,the surface state hybridization induced by the Ni NPs on NiN 4 caused ac hange in the adsorption strengths of intermediates and potential barriers for certain elementary steps of ECR, which optimized the reaction kinetics and boosts the ECR catalytic activities.…”

Advances and Challenges for the Electrochemical Reduction of CO2 to CO: From Fundamentals to Industrialization

“…Wang et al. developed an axial traction strategy to optimize the electronic structure of an Ni‐N 4 moiety by constructing an Ni site coordinated with four N atoms and one axial O atom (Ni‐N 4 ‐O/C) [81] . The Ni‐N 4 ‐O/C species exhibited a maximum FE CO of 99.2 % at −0.9 V. DFT calculations elucidated that the introduction of an axial O atom could optimize the surface state of the Ni‐N 4 moiety and enhance the charge polarization effect, thereby reducing the reaction barriers for the transformation of CO 2 to the intermediate *COOH.…”

High Capacity and Fast Kinetics of Potassium-Ion Batteries Boosted by Nitrogen-Doped Mesoporous Carbon Spheres

“…For the purpose of obtaining better electrochemical performances, it is necessary to further modify hard carbon materials. It is a proved fact that porosity structure is beneficial to enhance the contact between electrolyte and anode material, providing more active sites, shortening K-ion diffusion distance and accommodating volumetric expansion [14,[20][21][22][23]. In addition, heteroatom doping, especially N doping, has been applied to increase active sites of carbon materials, so as to promote K-ion adsorption and increase their electronic conductivity [24][25][26][27][28][29][30].…”