Engineering Plasma-Liquid Microdischarge Systems for Direct N₂‑to-NH₃ Conversion at Ambient Conditions

Area of Science:

• Chemical Engineering
• Plasma Physics
• Electrochemistry

Background:

• Ammonia (NH3) synthesis traditionally relies on energy-intensive processes like the Haber-Bosch method.
• Plasma micro-discharges at the water-electrode interface offer a novel route for NH3 production under ambient conditions.
• Device engineering is critical for optimizing plasma discharge performance and stability.

Purpose of the Study:

• To develop and engineer a hybrid electrochemical device for sustainable ammonia production.
• To investigate the role of solvated electrons generated via plasma-liquid interactions in NH3 synthesis.
• To optimize key operational parameters for enhanced NH3 yield and Faradaic efficiency.

Main Methods:

• Integration of a micro-plasma cathode within a hybrid electrochemical device.
• Systematic investigation of plasma-liquid gap, gas flow rate, discharge current, and cathode diameter.
• Analysis of ammonia yield and Faradaic efficiency under varying operational conditions.

Main Results:

• Achieved ammonia (NH3) synthesis directly from N2 and H2O using plasma micro-discharges.
• Solvated electrons from plasma-liquid interactions served as potent reducing agents, negating the need for catalysts.
• Optimized device engineering resulted in a Faradaic efficiency exceeding 70% and enhanced N2-to-NH3 yield.

Conclusions:

• Hybrid electrochemical device with a micro-plasma cathode enables efficient and sustainable ammonia production.
• System engineering optimization is crucial for advancing plasma-assisted nitrogen fixation.
• The developed technology shows potential for industrial scale-up of green ammonia synthesis.