A novel NOx-storage-reduction (NSR) catalyst of Pt/Ba/TiCeO was prepared by coprecipitationimpregnation method and the effects of the reaction atmosphere on its properties for NOx storage was investigated.The catalysts were characterized by means of N2 adsorption, X-ray diffraction (XRD) and temperature-programmed desorption (TPD).The results indicate that the specific surface areas of TiCeO and BaO/TiCeO were as high as 230 m2/g and 90 m2/g respectively.For the component of Ba, not only did it act as structural promoter for enhancing the structure stability of the catalysts Pt/Ba/TiCeO, but also it increased NOx storage capacity due to its basicity.Pt catalyzed oxidization of NO to NO2, and it is easier for NO2 to react with BaO/TiCeO to form nitrate than NO.TiCeO in Pt/Ba/TiCeO catalyst exhibited as both support and storage component in the NOx storage-reduction process.There were some active sites composed of Ba and TiCeO in the catalyst of Pt/Ba/TiCeO.The presence of SO2 has less effect on NOx storage capacity of Pt/Ba/TiCeO catalyst because the formed sulfate on the surface of the catalyst was unstable and was easily removed by reduction.%采用共沉淀-浸渍法制备了新型NOx储存-还原催化剂Pt/Ba/TiCeO,考察了不同反应气氛对载体和催化剂上NOx存储性能的影响,并用x射线衍射(XRD)和程序升温脱附(TPD)等方法对催化剂进行了表征.结果表明,Pt/Ba/TiCeO中TiCeO和BaO/TiCe具有较大比表面积(230 m2/g和90 m2/g),Ba不仅起结构助剂作用,使催化剂的结构稳定,而且Ba的碱性又有利于NOx的吸附.n主要起催化氧化作用,催化NO氧化生成NO2,NO2比NO更容易与BaO/TiCeO成盐,促进NOx的存储.Pt/Ba/TiCeO催化剂中存在一储存活性位,它们是Ba位与TiCeO位组合.SO2对Pt/BaO/TiCeO催化剂的NOx储存性能影响较小,主要是Pt/BaO/TiCeO上形成的硫酸盐分解还原峰温度较低(410℃),硫化物易分解还原脱除,其抗硫中毒能力较强.
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