Palladium Enhanced Iron Active Site - An Efficient Dual-Atom Catalyst for Oxygen Electroreduction

Area of Science:

• Materials Science
• Electrochemistry
• Catalysis

Background:

• Metal-nitrogen-carbon (M-C/N) materials are promising electrocatalysts for the oxygen reduction reaction (ORR).
• Achieving high activity and long-term durability in both alkaline and acid media remains a challenge for M-C/N catalysts.

Purpose of the Study:

• To develop a novel dual-atom electrocatalyst with enhanced ORR performance.
• To investigate the synergistic effects of iron (Fe) and palladium (Pd) in a nitrogen-doped carbon matrix (C/N).

Main Methods:

• Synthesis of Fe&Pd-C/N electrocatalyst using a metal-containing ionic liquid.
• Characterization using X-ray absorption fine structure (XAFS), X-ray photoelectron spectroscopy (XPS), and aberration-corrected transmission electron microscopy (AC-TEM).
• Electrochemical evaluation in alkaline and acid media, and Density Functional Theory (DFT) calculations.

Main Results:

• Verified a dual-atom configuration with Fe^+2.x-N₄ coupled Pd²⁺-N₄ sites and uniform spatial distribution.
• Fe&Pd-C/N exhibited superior ORR activity and durability compared to commercial Pt/C (20%).
• DFT calculations revealed Pd enhances Fe catalytic activity through electronic structure modification.

Conclusions:

• The Fe&Pd-C/N electrocatalyst shows excellent performance in alkaline and acid media, attributed to the synergistic Fe-Pd dual-atom sites.
• This catalyst demonstrates significant potential for applications in zinc-air batteries and hydrogen-air fuel cells.