Directional Manipulation of Electron Transfer by Energy Level Engineering for Efficient Cathodic Oxygen Reduction

Area of Science:

• Materials Science
• Electrochemistry
• Catalysis

Background:

• Electron transfer is crucial for energy conversion efficiency in devices.
• Nitrogen-coordinated single metal sites (M-N4) are promising electrocatalysts.
• Controlling electron transfer in M-N4 catalysts remains challenging for efficiency.

Purpose of the Study:

• To demonstrate how energy level structure influences electron transfer in M-N4 catalysts.
• To propose and validate an energy level engineering strategy for improved catalyst performance.
• To design high-performance electrocatalysts for energy devices.

Main Methods:

• Utilized classical iron phthalocyanine (FePc) molecule/carbon models to study electron transfer mechanisms.
• Engineered molecular energy levels by modifying FePc structure with nitro groups.
• Fabricated and tested electrocatalysts based on the energy level engineering strategy.

Main Results:

• Demonstrated that modulating FePc molecular structure with nitro groups enhances interfacial electronic coupling.
• Achieved efficient charge transfer from carbon to the engineered FePc-β-NO2 molecule.
• Developed zinc-air batteries with ultrahigh performance, surpassing most M-N4 catalysts.

Conclusions:

• Energy level engineering provides a universal strategy for manipulating electron transfer in electrocatalysts.
• This approach offers a new paradigm for designing efficient and stable M-N4 electrocatalysts.
• The developed strategy significantly boosts the performance of energy devices.