中文摘要：

通过改进的溶胶凝胶法结合浸渍法制备了一系列Pt/x Ba-（30-x）Ce/γ-Al2O3（x=10、15、20,x为质量分数）型NSR催化剂,并利用XRD、BET、H2-TPR和NO-TPD对其性能进行了表征。结果表明,Ba主要以BaCO3形式存在,CeO2晶粒粒径随着x值增大先减小后增大,且以无定型形式存在于催化剂中。随着Ce含量的增加,高温还原峰温度先降低后升高。NOTPD结果表明,吸附于催化剂表面的NOx在低温时具有较好的热稳定性;通过NOx完全存储实验,探究了不同Ba/Ce比对催化剂NOx存储性能的影响。结果表明,当x=15时,催化剂的NOx存储量最大,NOx穿透时间达7 min,吸附稳定时NO2/NOx比为28%,NOx存储效率达47.1%,具有最佳的NOx存储性能。

英文摘要：

In order to explore the effects of Ba/Ce ratio on the NOx storage performance of the catalyst,a series of Pt/xBa-（30-x ）Ce/y-Al2O3（x =10,15,20,x is a mass fraction） NSR catalysts were prepared by a modified sol-gel method combined with an impregnation method,and their properties were characterized by means of X- ray diffraction （XRD）,specific surface area analysis （ BET）, temperature programmed reduction of H2（ H2- TPR） and temperature programmed desorption of NO （NO- TPD）. The results indicate that Ba mainly exists in the form of BaCOg,and CeO2 is present in the amorphous form. With the increase of x value,CeO2 grain size decreases firstly and then increases. With the increase of Ce content,the high temperature reduction peak has a similar tendency with that of CeO2 grain size. The NO-TPD results show that the NO; adsorbed on the surface of the catalyst has a better thermal stability with the temperature below 350 益.The effects of Ba/Ce ratio on the NOx storage performance were investigated by a simulated gas test platform. The results show that the NOx storage capacity of the Pt/15Ba-15Ce/y-Al2O3 catalyst has a maximum value of 47. 1% ,and the NOX breakthrough time is 7 min. When the storage process completes,the NO2/NOX ratio of Pt/ 15Ba-15Ce/γ-Al2O3 catalyst is 28 %. The NOX storage efficiency increases firstly and then decreases,and different Ba/Ce ratios have great influences on the storage path of the catalyst. The catalyst presents excellent NOX storage performance when the Ba/Ce ratio is 1.0. The experimental results provide a reference for the optimal design and application of NSR catalyst in the field of diesel exhaust after-treatment system.