Review of the Catalytic System, Synthetic Process, and Support Morphological Research in Selective Catalytic Oxidation of Ammonia

Ammonia leakage emissions are an important environmental issue in the management of air pollutants. This paper summarizes the current development in the field of the selective catalytic oxidation of ammonia (NH3-SCO) in the past 20 years; briefly introduces the common catalyst preparation methods and carrier types; focuses on noble metal based catalyst systems with Ag, Pt, Ru, Pd, and other noble metals as the mainstay and transition metal based catalysts with Fe, Mn, V-Ce, and Cu monomer or their oxides as the mainstay and their modification methods; outlines the several reaction mechanisms common to different catalyst systems in the NH3-SCO reaction; and presents the reaction mechanism of NH3 and CO co-oxidation. The emergence of low-temperature, high activity, and high selectivity NH3-SCO catalysts requires attention to the graded dehydrogenation reaction of NH3, and therefore we strongly recommend the development of innovative catalysts with strong NH3 adsorption activation and O-2 activation capabilities.