The why and how of NO_x electroreduction to ammonia

Electroreduction of the oxidized forms of nitrogen (NO_x) has been studied for decades, with the most recent intense research focusing on the conversion of nitrate to ammonia. Here we discuss how such technology might, or might not, be able to contribute to sustainable ammonia (NH₃) production and highlight its conceptual and experimental differences from the electrosynthesis of NH₃ from dinitrogen. A generic experimental protocol for NO_x-to-NH₃ studies is proposed and discussed along with the situations where control experiments with a ¹⁵N-labelled nitrogen source may not be required. [Figure not available: see fulltext.].