Delafossite Ag ₂ CuMnO ₄ is a Novel Catalytic Material for Low‐Temperature Oxidation of CO and NH ₃

Ternary oxide of silver, copper, and manganese (Ag₂CuMnO₄) was prepared by hydrothermal synthesis in an alkaline solution. The prepared sample was characterized by a delafossite crystal structure without any other crystallized phases. The catalytic properties of Ag₂CuMnO₄ in oxidation reactions using molecular oxygen were investigated. High catalytic activity was found for Ag₂CuMnO₄ in the CO oxidation at room temperature, while ammonia oxidation occurred above 100 °C. Ammonia oxidation resulted in the formation of N₂O/N₂ or NO/NO₂ products depending on the reaction temperature. As a result of the reaction exposure on Ag₂CuMnO₄ during heating up to 400 °C, a modification of surface composition with preservation of the delafossite structure was found. Oxide Ag₂CuMnO₄ was shown to be operating in wet CO oxidation under ambient conditions. Obtained data emphasize that Ag₂CuMnO₄ can be considered as a novel and prospective catalytic material with a high potential of application for oxidation processes at low temperatures including ambient conditions.