PdFe Single-Atom Alloy Metallene for N₂ Electroreduction.

Area of Science:

• Materials Science
• Electrochemistry
• Catalysis

Background:

• Single-atom alloys (SAAs) show potential for electrocatalytic nitrogen reduction reaction (NRR).
• Comprehensive experimental and theoretical studies on SAAs for NRR are limited.
• Developing efficient and stable NRR electrocatalysts is crucial for sustainable ammonia production.

Purpose of the Study:

• To develop and investigate a novel PdFe single-atom alloy metallene (PdFe1) as an electrocatalyst for NRR.
• To elucidate the catalytic mechanism of PdFe1 for NRR through experimental and theoretical analyses.
• To evaluate the performance, selectivity, and stability of PdFe1 for the nitrogen reduction reaction.

Main Methods:

• Synthesis of PdFe1 single-atom alloy metallene.
• Electrocatalytic performance testing for NRR, including ammonia yield and Faradaic efficiency.
• Operando X-ray absorption and Raman spectroscopy for in-situ characterization.
• Theoretical computations (e.g., DFT) for mechanistic investigations.

Main Results:

• PdFe1 exhibited exceptional NRR performance with an NH3 yield of 111.9 μg h⁻¹ mg⁻¹ and 37.8% Faradaic efficiency at -0.2 V (RHE).
• The catalyst demonstrated excellent long-term stability over 100 hours of electrolysis.
• Mechanistic studies identified Pd-coordinated Fe single atoms as active sites, facilitating N2 activation and suppressing hydrogen evolution.

Conclusions:

• PdFe1 single-atom alloy metallene is a highly effective and robust electrocatalyst for NRR.
• The catalyst's performance is attributed to efficient N2 activation, reduced protonation barriers, and suppressed hydrogen evolution.
• This work provides fundamental insights into SAA electrocatalysis for NRR, paving the way for future catalyst design.