Delafossite Ag2CuMnO4 is a Novel Catalytic Material for Low‐Temperature Oxidation of CO and NH3.

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. [ABSTRACT FROM AUTHOR]