NOx storage performance of Pt/Mg-Al-O catalyst

A series of Pt/Mg-Al-O catalyst samples with different Mg/Al molar ratios were prepared by coprecipitation followed by impregnation, and the catalyst samples were characterized by XRD and TPD. The effects of reaction conditions on NO, storage over the support and the catalyst were studied. The results showed that NO2 storage was more preferable to NO storage. Pt could catalyze the oxidation of NO, resulting in much higher NOx storage capacity. The NOx storage capacity at saturation increased with the increase of Mg/Al molar ratio at 350 degreesC, there was an interaction between Mg and Al, and the addition of Al2O3 was advantageous to the storage of NOx. The promoting effect of Al2O3 was more pronounced at low temperature ( < 300 degreesC). The catalyst with n (Mg)/n (Al) = 3 possessed good performance for NOx storage in the range from 150 to 400 degreesC and had a maximum at 300 degreesC.