Abstract
Kylie A. Vincentopened a discussion of the paper by John T. S. Irvine: Do youhave a sense of what target faradaic efficiency will be needed to make viableelectrode systems for ammonia production? Will it be necessary to developelectrodes with perfect selectivity for ammonia, or will device-engineering solu-tions overcome these challenges?John T. S. Irvineanswered: Near 100% faradaic efficiency is needed forammonia and hydrogen production combined. Of this I suggest at least 50% ofthe produced hydrogen stays in the ammonia. This would be sufficient to allowengineering approaches to deliver an efficient solution.Richard A. Catlowsaid: You are employing a complex quaternary oxide. Canyou say more about what properties this composition is optimising?John T. S. Irvinereplied: The composition is chosen to optimise conductivityand stability and is directed by the relevant ion size and nominal oxygen-vacancycontent.Wenbo Gaoasked: Could the hydride-ion conductor be used for electro-chemical ammonia synthesis?John T. S. Irvineresponded: Yes, but care will be needed to develop suitableelectrochemical systems due to the reactivity of hydride.