A Comprehensive Review of Transition Metal Catalysts in Ammonia Catalytic Oxidation: Recent Advances and Future Perspectives

This paper summarizes the application of transition metal catalysts in ammonia oxidation and highlights their role in selective catalytic oxidation (NH3–SCO). With the acceleration of industrialization and urbanization, ammonia gas has become an important industrial raw material and a typical toxic waste gas. Ammonia is not only harmful to human health, but the NOx it generates can lead to environmental problems such as acid rain and eutrophication. Therefore, it is crucial to develop highly efficient ammonia treatment technologies. This paper discusses the sources and hazards of ammonia gas, as well as existing treatment methods, including biological, absorption, and heterogeneous catalytic methods. Then, it delves into the basic principles of ammonia oxidation, including reaction mechanisms, intermediates, and reaction pathways. It also analyzes the structural characteristics of catalysts, such as the valence state of active metals, oxygen type, particle size, and the effects of single - atomic catalysts. In terms of catalyst systems, the research progress of transition metal catalysts like Cu, Fe, Mn, and Co is emphasized, and the synergistic effects between the catalyst structure, active components, and promoters are discussed. Finally, the paper summarizes the advantages and challenges of transition metal catalysts in ammonia oxidation and offers prospects for future research directions. Through a thorough analysis of the catalyst structure and reaction, mechanism this paper provides a theoretical basis and research directions for designing more efficient and selective ammonia oxidation catalysts.