Electrochemical Synthesis of Hydroxylamine

Hydroxylamine (NH2OH) serves as an important industrial feedstock. The conventional production and transportation of NH2OH requires harsh conditions. Recently, electrochemical hydrogenation of nitrogen–containing oxidative species, such as nitrate, nitrite and nitric oxide (NO3–/NO2–/NO), into hydroxylamine has been developed as a sustainable strategy. However, the over–hydrogenation product of ammonia is preferentially obtained under electroreduction condition. Thus, the rational design of catalysts structure is crucial to selective electrosynthesis of NH2OH. In this minireview, we summarize recent advances in electrochemical synthesis of NH2OH with emphasis on the design of catalysts structure. Electrochemical synthesis strategy we discussed is categorized by the existence form of product, including indirect electrosynthesis and direct electrosynthesis. Finally, the techno–economic analysis (TEA) of electrochemical NH2OH production and outlook of performance improvement strategies are carried out to further guide the optimization of reaction system.