Electrochemical ammonia synthesis under ambient conditions (below 100 °C and at atmospheric pressure) provides an attractive alternative to the fossil fuel-intensive Haber-Bosch process. It would enabling on-site on-demand ammonia production, and be powered by renewable energy. Most experimental studies, thus far, only report small quantities of ammonia, produced with low selectivity, reflecting significant scientific and technical challenges. Moreover, both ammonia itself and other labile nitrogen-containing compounds, such as nitrates, amines, nitrites, nitrogen oxides, etc., are typically present in the gas stream, atmosphere, or even the catalyst itself. This makes it difficult to trace whether the NH3 formed is derived from molecular nitrogen. The field is in need of a standardized set of control experiments and benchmarking protocols for the reaction. We propose a rigorous procedure for the reliable detection and quantification of electrochemical N2reduction to NH3, with a control experiment using 15N2 as an indispensable step. By following this protocol, we successfully demonstrate ammonia synthesis using lithium electrodeposition in tetrahydrofuran. We anticipate that our procedure will help other scientists distinguish false positives from true breakthroughs. It will enable the field to advance much faster towards practical electrochemical technologies for the electrochemical reduction of N2 to ammonia.

Quantitative protocol for the electroreduction of N2 to NH3 under ambient conditions

2019 Spring National Meeting

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