Performance of the CeZrO2 mixed oxide in the NOx decomposition

The present work aims to evaluate the performance of the CeZrO2 mixed oxide for the NOx decomposition in the absence of a noble metal. The Ce75Zr25O2 mixed oxide was prepared by co-precipitation of hydroxides and was characterized by X-ray diffraction (XRD) before and after pre-treatments, thermogravimetric analysis (TG) and temperature programmed desorption of NO (TPD). XRD results allowed confirming the formation of a solid solution. TG results showed slight loss of mass during the reduction of the mixed oxide. TPD results showed NO decomposition even at room temperature either for reduced or calcined samples, however a significant decrease of the temperature of the NO decomposition besides an increasing amount of N2 for the reduced sample, which is attributed to superficial structure changes of the mixed oxide.