Session: Research Posters

Paper Number: 165739

Ammonia Synthesis via Synergistic Plasma-Electrochemical Nitrogen Reduction 

Ammonia (NH₃) is a critical chemical used in fertilizer production, energy storage, and hydrogen carriers. However, its industrial synthesis via the Haber-Bosch process remains highly energy-intensive, requiring extreme temperatures and pressures (400–500°C, 150–300 bar) while consuming significant fossil fuel resources. Developing an alternative ammonia production pathway under ambient conditions is essential for reducing energy consumption and greenhouse gas emissions. This study explores a novel plasma-electrochemical approach to nitrogen reduction using a non-thermal high-voltage plasma system coupled with an electrochemical H-cell reactor. By integrating plasma activation and electrochemical reduction, this approach enables nitrogen fixation under mild conditions, providing a sustainable alternative to conventional methods.

The experimental setup consists of an H-cell reactor where nitrogen gas (N₂) is introduced into a sulfuric acid (H₂SO₄) electrolyte. Plasma discharge is generated using high-voltage AC and DC configurations to dissociate N₂ and create reactive nitrogen species, which subsequently react in the electrolyte. Various catalysts, including Pt, Pd, NbN, NbO₂, and carbon-supported materials, are tested to enhance ammonia yield by facilitating nitrogen activation and electrochemical reduction. Key reaction parameters such as electrolyte composition (acid, base, and salt), acid concentration, gas purging conditions (Ar vs. N₂), plasma discharge mode (AC vs. DC), and pH sensitivity are systematically studied to determine their effects on NH₃ production efficiency. Temperature effect is also studied for drawing conclusion.

Our findings demonstrate that plasma-generated nitrogen species significantly enhance nitrogen fixation rates, with electrochemical pathways playing a crucial role in ammonia formation. The synergy between plasma and electrochemistry allows ammonia synthesis to occur at room temperature and atmospheric pressure. Comparative studies indicate that noble metal catalysts, particularly Pt and Pd, exhibit high catalytic activity, while transition metal nitrides offer a cost-effective alternative with promising efficiency. Additionally, varying the electrolyte composition influences reaction kinetics and ammonia selectivity, highlighting the importance of optimizing electrochemical conditions.

Further analysis of energy input versus ammonia yield suggests that plasma-electrochemical interactions can lower the energy requirements compared to thermal methods, offering a more sustainable pathway for ammonia production. The ability to generate ammonia under ambient conditions presents opportunities for decentralized production and on-site fertilizer synthesis, particularly in remote or off-grid locations. Future work will focus on improving energy efficiency, optimizing catalyst stability, and scaling up the process for industrial applications. By leveraging plasma-electrochemical interactions, this approach aligns with global efforts toward sustainable chemical manufacturing and carbon-neutral ammonia production, paving the way for more efficient and environmentally friendly nitrogen fixation technologies.

 

Presenting Author: Snigdha Rashinkar University of Massachusetts Lowell

Presenting Author Biography: I am a 6+ years experienced Materials Engineer pursuing my PhD in Mechanical Engineering from University of Massachusetts, Lowell. I did my MS in Materials Engineering from University of Texas at Arlington. I have worked on exhaust systems of commercial and non-commercial automobiles with Faurecia Clean Mobility at a technical center in Columbus, Indiana as a Materials Engineer. I have worked on fuel rail injectors at Robert Bosch Pvt. Ltd. as a Materials Engineer in India. My focus of study in PhD is Ammonia production using non thermal plasma in electrocatalysis method and compare the results with Ammonia production in Fuel cells.

Authors:

Snigdha Rashinkar University of Massachusetts Lowell
Dr Fuquiang Liu University of Massachusetts Lowell