Catalytic activity and mechanism of selective catalytic oxidation of ammonia by Ag–CeO(2) under different preparation conditions

Given the problem of the high-temperature window of CeO(2) catalyst activity, this study evaluated the catalytic properties of Ag/CeO(2) prepared by changing the preparation methods and loadings. Our experiments showed that Ag/CeO(2)-IM catalysts prepared by the equal volume impregnation method could have better activity at lower temperatures. The Ag/CeO(2)-IM catalyst achieves 90% NH(3) conversion at 200 °C, and the main reason is that the Ag/CeO(2)-IM catalyst has more vital redox properties, and the NH(3) catalytic oxidation temperature is lower. However, its high-temperature N(2) selectivity still needs to be improved and may be related to the less acidic sites on the catalyst surface. On both catalyst surfaces, the i-SCR mechanism governs the NH(3)-SCO reaction.