The effective elimination of N2O from automobile exhaust at low temperatures poses significant challenges. Compared to other materials, supported RhOx catalysts exhibit high N2O decomposition activities, even in the presence of O2, CO2, and H2O. Metal additives can enhance the low-temperature N2O decomposition activities over supported RhOx catalysts; however, the enhancement mechanism and active sites require further investigation. In this study, we demonstrate the significant enhancement of the low-temperature N2O decomposition activity of a monoclinic ZrO2-supported Rh catalyst [Rh(1)/ZrO2] with Ir addition in the presence of N2O + O2 + CO2 + H2O. The promotional effect of Ir and the active sites on N2O decomposition in Rh(1)-Ir(1)/ZrO2 (Rh = 1 wt % and Ir = 1 wt %) were investigated by kinetic studies and in situ spectroscopic methods, including X-ray absorption spectroscopy, ambient-pressure X-ray photoelectron spectroscopy, and ultraviolet-visible spectroscopy. These results indicate that both surface Rh and Ir species in Rh(1)-Ir(1)/ZrO2 were active sites for N2O catalytic decomposition at low temperatures, and Ir augmentation promoted the desorption of gaseous O2, which are regarded as key steps in N2O decomposition.
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