Breaking the Performance Limit of Pure Metals for N₂ Electroreduction

Area of Science:

• Electrochemistry
• Materials Science
• Sustainable Chemistry

Background:

• Electrocatalytic nitrogen reduction reaction (NRR) is a promising route for sustainable ammonia synthesis.
• Challenges include low N2 concentration and competing hydrogen evolution reaction (HER) on conventional catalysts.

Purpose of the Study:

• To develop a universal micro/nanoengineering strategy to enhance NRR efficiency.
• To address limitations of low N2 concentration and intermediate adsorption.

Main Methods:

• Fabrication of three-phase-interface-optimized hollow fiber (HF) electrodes.
• Utilizing Fe-based HF electrodes as a proof of concept.
• Investigating mechanistic aspects through experimental studies.

Main Results:

• Fe-based HF electrodes achieved NH3 yield rate of 27.1 µg h⁻¹ cm⁻² and FE of 3.5%.
• Performance was significantly enhanced compared to planar electrodes (∼60-fold yield, ∼35-fold FE).
• The HF architecture promoted N2 diffusion, suppressed HER, and activated N≡N bond cleavage.

Conclusions:

• The HF electrode strategy effectively enhances local N2 enrichment and optimizes intermediate adsorption for NRR.
• This micro/nanoengineering approach shows broad applicability across different metals (Fe, Cu, Ni).
• The developed strategy presents a general platform for advancing sustainable ammonia electrosynthesis.