Adapting Atomic Configuration Steers Dynamic Half-Occupied State for Efficient CO₂ Electroreduction to CO

Area of Science:

• Materials Science
• Electrochemistry
• Catalysis

Background:

• Understanding the electronic structure of atomically dispersed transition-metal-nitrogen-carbon catalysts (ADTCs) is crucial for their catalytic performance and reaction mechanisms.
• Dynamic electronic disturbances at metal centers under realistic electrocatalytic conditions are often overlooked, leading to ambiguous structure-property correlations.

Purpose of the Study:

• To investigate the dynamic electronic behaviors of transition-metal centers in ADTCs during CO2 electroreduction.
• To establish a precise activity descriptor for CO2-to-CO conversion based on dynamic electronic and geometric configurations.

Main Methods:

• Utilized operando time-resolved X-ray absorption spectroscopy to probe dynamic electronic changes in transition-metal centers.
• Analyzed adaptive variations in metal-ligand configuration and d-orbital occupation under working conditions.

Main Results:

• Identified a dynamic axial d^2 electron state as a precise activity descriptor for CO2-to-CO conversion.
• Demonstrated that a half-occupied d-electron state optimizes binding with intermediates, significantly enhancing CO production.
• Observed a 1-2 order of magnitude kinetics enhancement for the optimal d-electron state compared to fully occupied or unoccupied states.

Conclusions:

• Established the first empirical correlation between dynamic electronic/geometric configuration and catalytic kinetics in ADTCs.
• Paved a new pathway for modulating catalysts and designing highly efficient electrocatalytic CO2 reduction pathways.