Electrocatalytic Ammonia Oxidation Reaction: Selective Formation of Nitrite and Nitrate as Value-Added Products.

Ammonia (NH) plays a pivotal role as a hydrogen carrier, offering a carbon-free energy alternative for sustainable energy systems. The ammonia electrooxidation reaction (AmOR) emerges as a promising avenue to leverage NH₃ in energy conversion and environmental applications. This review explores the multifaceted importance of NH oxidation through three primary strategies: its integration into fuel cell technology for clean energy generation, its use in wastewater treatment for ammonia removal, and its application in electrolyzer setups for producing value-added products. Special emphasis is placed on oxidizing NH to nitrite (NO ) and nitrate (NO ) in electrolyzers as a potential alternative to the energy-intensive Ostwald process. The review highlights recent advances in catalyst development for efficient NO /NO synthesis, the influence of the pH on reaction selectivity, and various reported experimental AmOR solutions. By addressing these critical aspects, this work aims to underscore the potential of NH oxidation in electrolyzers for sustainable energy solutions. Potential future research directions and challenges are also discussed.