Engineering 3d-2p-4f Gradient Orbital Coupling to Enhance Electrocatalytic Oxygen Reduction.

Area of Science:

• Materials Science
• Electrochemistry
• Catalysis

Background:

• Developing efficient and economical electrocatalysts for the oxygen reduction reaction (ORR) is crucial for energy conversion technologies.
• Intrinsic scaling relations often limit the activity of ORR electrocatalysts due to thermodynamic inhibition.

Purpose of the Study:

• To propose a novel gradient orbital coupling strategy for tuning ORR performance.
• To construct Co 3d-O 2p-Eu 4f unit sites on a Eu2O3-Co model to overcome scaling relation limitations.

Main Methods:

• Utilizing a gradient orbital coupling strategy to modify the electronic properties of Co sites.
• Constructing Co-O-Eu unit sites to tune the interaction between Co 3d, O 2p, and Eu 4f orbitals.
• Analyzing the impact of orbital coupling on e_g occupancy and O-O bond strength.

Main Results:

• The gradient orbital coupling strategy optimized e_g occupancy of Co sites and weakened the O-O bond.
• The optimized catalyst exhibited superior onset and half-wave potentials compared to commercial Pt/C and other Co-based catalysts.
• The catalyst demonstrated excellent selectivity, durability, and performance in Zn-air batteries.

Conclusions:

• The proposed gradient orbital coupling strategy effectively breaks the scaling relation for ORR electrocatalysts.
• This approach offers a new perspective for electronic modulation strategies in catalyst design.
• The novel Eu2O3-Co based catalyst shows significant potential for practical energy conversion applications.