A Comparative Mini-Review on Transition Metal Oxides Applied for the Selective Catalytic Ammonia Oxidation (NH 3 -SCO).

The selective catalytic oxidation of NH 3 (NH 3 -SCO) into N 2 and H 2 O is an efficient technology for NH 3 abatement in diesel vehicles. However, the catalysts dedicated to NH 3 -SCO are still under development. One of the groups of such catalysts constituted transition metal-based catalysts, including hydrotalcite-derived mixed metal oxides. This class of materials is characterized by tailored composition, homogenously dispersed mixed metal oxides, exhibiting high specific surface area and thermal stability. Thus, firstly, we give a short introduction to the structure and composition of hydrotalcite-like materials and their applications in NH 3 -SCO. Secondly, an overview of other transition metal-based catalysts reported in the literature is given, following a comparison of both groups. The challenges in NH 3 -SCO applications are provided, while the reaction mechanisms are discussed for particular systems.