Coupling Nitrate Reduction Reaction With Ammonia Recovery: Perspectives on Principles and Engineering

ABSTRACT Electrochemical nitrate reduction reaction (NO 3 RR) refers to the route of converting nitrate (NO 3 − ) to ammonia (NH 3 ). However, NH 3 dissolved in the post‐reaction solution is limited for direct reuse toward downstream purposes, thereby undermining the application potentials and economic viability of NO 3 RR. Instantaneous NH 3 recovery after NO 3 − conversion reduces the entropy of the system, thermodynamically favoring the forward reaction. NH 3 separation is necessary for both resource recovery and environmental safety considering its toxicity. Coupling NO 3 RR with NH 3 recovery presents a promising solution for decentralized nitrogen management, particularly in areas with limited access to the power grid and commercial fertilizers. In this perspective, principles and engineering design of NH 3 recovery are introduced, with a highlight on heat as a suitable driving force. Looking forward, enhancing the reactant and product selectivity by smart materials design will facilitate the treatment of different nitrogen sources, and incorporating current energy infrastructures leads a way of enhancing access to electricity, sanitation and fertilizers.