Abstract: La-Al2O3, Ce0.63Zr0.37O2 (OSM1) and Ce0.5Zr0.3Mn0.2O2(OSM2) were prepared by co-precipitation method. The catalysts of Pt/La-Al2O3 and Pt/OSM were prepared by impregnation with platinum loading of 1%(w). The monolithic catalysts were investigated for the selective catalytic reduction of NO by methane and were characterized by XRD, H2-TPR and XPS. The results reveal that Pt/OSM1 and Pt/OSM2 have excellent purification properties for the catalytic reduction of NO by methane in the condition of 0.8% O2. Both CH4 and NO reach 100% conversion at 500 ℃ over Pt/OSM1, while over Pt/OSM2 the conversions of CH4 and NO are 73% and 100%, respectively. Over Pt/La-Al2O3, CH4 and NO reach almost 100% conversions only when O2 content is below 0.4% at 500 ℃. As O2 is excessive, the activity of Pt/La-Al2O3 decreases sharply. The results of H2-TPR reveal that the interaction of Pt and OSM leads to the formation of reduction phase at low temperature. The high activity of NO reduction by methane in the excessive presence of O2 is due to the interaction of Pt and OSM and the oxygen storage capacity of OSM.

Key words: Oxygen storage materials (OSM), La-Al2O3, Platinum, Monolith catalyst, Selective catalytic reduction