Argon blank experiments verified the source of the ammonia was from the input N2 gas. In an industrial setting, where devices would be operational for significantly longer periods of time, the efficiency losses associated with intercalation would become negligible. To corroborate this point and verify that the initial phase of electrochemistry (where the potential of the carbon cathode decreases) does not contribute to the ammonia produced, we conducted a short-term experiment. The experiment was stopped before the potential plateaued, after 23 Coulombs had passed (Supplementary Figure .2) and no ammonia was produced during this experiment. This supports the notion that the initial phase is due to intercalation, which does not contribute to ammonia production. As such, if we can neglect the charge passed during the initial charge (20 Coulombs) from the Faradaic efficiency calculation we can deduce that the Faradaic efficiency to NH3 in the following 20 coulombs would be as high as 24 %.