Nitrogen fixation in a non-equilibrium spatially distributed electric field.

Area of Science:

• Plasma Chemistry
• Chemical Engineering
• Materials Science

Background:

• The Haber-Bosch process, crucial for nitrogen fixation, is highly energy-intensive.
• There is a pressing need for sustainable and energy-efficient alternatives for nitrogen fixation.

Purpose of the Study:

• To introduce and evaluate a non-equilibrium spatially distributed electric field (SD-EF) strategy for nitrogen fixation in ambient air plasma.
• To enhance nitrogen conversion efficiency and product yield compared to conventional methods.

Main Methods:

• Development of an optimized SD-EF strategy for plasma-assisted nitrogen fixation.
• Utilizing a photonic crystal fiber diagnostic for in-situ quantification of molecules and ions in gas-liquid plasma.
• Investigating the activation of ozone (O3) and N2 vibrational excitation (N2(v)) sub-mechanisms.

Main Results:

• The optimized SD-EF strategy achieved a NO_x^- yield of 9.8 mmol/h, tripling that of a uniform electric field.
• Achieved three times higher N₂ conversion than most discharge configurations with similar or lower energy consumption.
• Identified simultaneous activation of O3 and N2(v) kinetic networks as key to high yields.

Conclusions:

• The SD-EF strategy offers a highly efficient and promising alternative for plasma-assisted nitrogen fixation.
• The developed in-situ diagnostic technique is valuable for understanding plasma-chemical processes.
• This approach has broad applicability for other plasma-assisted chemical conversion processes.