A Method of Synthesising Atomically Dispersed CO2–N6 and Fe–N4 Costructures Anchored on Hierarchical Porous Carbon Host

Opportunity

Rechargeable metal-air batteries, reliant on electrocatalysts for the oxygen reduction reaction (ORR), are emerging as next-generation renewable energy storage systems. Polynary transition-metal atom catalysts are poised to replace Pt-based catalysts for ORR. Regulating the local configuration of atomic catalysts is thus crucial for enhancing performance. This technology offers a novel approach to achieve this. 

Technology

This invention introduces a precise synthesis strategy to design and construct atomically dispersed and nitrogen-coordinated ternary-atom centred sites anchored on CNTs-grafted hollow carbon. The unique atomic ORR catalyst outperforms those with only Co₂-N₆ or Fe-N₄ sites in both alkaline and acidic conditions. Density functional theory calculations reveal the synergistic effect of Co₂-N₆ or Fe-N₄ sites, which induce a higher filling degree of Fe-d orbitals and improve the binding capability to *OH intermediates. This ternary-atom catalyst is a promising alternative to Pt for driving cathodic ORR in zinc-air batteries.  

Figure 1: Schematic of the synthesis strategy of Co2/Fe–N@CHC and corresponding TEM images

Applications & Advantages

Main application areas include catalysts for ORR, zinc-air batteries and energy storage systems. 

Advantages: 

• Co₂-N₆ and Fe-N₄ sites provide superior performance for ORR 
• Exhibits higher power density in zinc-air batteries compared to Pt/C-based catalysts
• Demonstrates improved cycling stability compared to Pt/C-based catalysts