Progress and prospects in electrocatalytic ammonia synthesis reactors

Driven by the demand for green ammonia and sustainable energy technologies, electrochemical ammonia synthesis has attracted increasing attention due to its mild operating conditions, compatibility with renewable energy, and low-carbon potential. However, prior studies have focused primarily on catalyst development, while systematic analyses of reactor engineering remain limited, constraining industrial translation. This review provides a comparative examination of electrochemical ammonia synthesis reactors, including single-chamber and H-type electrolyzers, continuous-flow reactors, and membrane electrode assemblies, with an emphasis on mass transfer, current density, faradaic efficiency, and scalability. Key reactor engineering strategies-such as interface optimization, three-phase regulation, and membrane and flow-channel design-are summarized. Finally, future perspectives are discussed, highlighting durable catalysts, stable and low-cost membranes, modular continuous reactors, and integration with renewable energy systems to enable efficient, low-carbon, and scalable ammonia production.