Plasma-Assisted Ammonia Conversion: Mechanisms, Reactor Physics and Emerging Directions

Abstract

Ammonia (NH₃) is a key nitrogen-containing compound with significant environmental and energy implications. Its emission from agricultural, industrial and waste treatment processes contributes to air pollution and secondary aerosol formation. At the same time, ammonia is increasingly recognized as a carbon-free hydrogen carrier. Non-thermal plasma (NTP) technology has emerged as a promising approach for both ammonia removal and decomposition due to its ability to activate stable molecules under mild conditions. This review presents a comprehensive overview of plasma-assisted ammonia conversion, focusing on reaction mechanisms, plasma physics fundamentals, reactor configurations and recent developments. Particular attention is given to the roles of electron energy distribution, reactive species generation and plasma-catalytic coupling. The challenges associated with energy efficiency, by-product control and scale-up are critically discussed. Finally, future research directions are proposed, highlighting the integration of plasma with catalysis and renewable energy systems.