采用共沉淀法制备了Ce0.65Zr0.35O2(CZ)储氧材料,分别以乙醇-水、丙醇-水、乙二醇-水、丙三醇-水体系对沉淀物进行陈化,研究了醇的种类对CZ及其负载的单Pd催化剂性能的影响。对CZ进行了扫描电镜(SEM),N2-吸脱附分析,对Pd/CZ进行了粉末X...采用共沉淀法制备了Ce0.65Zr0.35O2(CZ)储氧材料,分别以乙醇-水、丙醇-水、乙二醇-水、丙三醇-水体系对沉淀物进行陈化,研究了醇的种类对CZ及其负载的单Pd催化剂性能的影响。对CZ进行了扫描电镜(SEM),N2-吸脱附分析,对Pd/CZ进行了粉末X射线衍射(XRD)、X射线光电子能谱(XPS)、储氧量(OSC)和程序升温还原(H2-TPR)的表征,并考察了三效催化性能。结果表明,醇的种类对CZ及Pd/CZ的性能有显著影响。在乙醇–水和丙醇–水陈化体系中制备的CZ分散性高,颗粒堆积松散,比表面积和孔径大,孔容高,且具有优异的热稳定性,其中丙醇–水陈化体系中制备的CZ老化后比表面积和孔容分别可达28 m2/g和0.1 m L/g,具有最高的热稳定性,其负载的单Pd催化剂在老化后对C3H8、CO和NO转化显著优于乙二醇–水和丙三醇–水陈化体系中制备的CZ所制备的催化剂。展开更多
The adsorption of CO2 and NO on supported Pd catalysts has been studied by using TPD-MS method and the adsorbed surface species were discussed based on literatures. The amount and intensity of basic sites increase whe...The adsorption of CO2 and NO on supported Pd catalysts has been studied by using TPD-MS method and the adsorbed surface species were discussed based on literatures. The amount and intensity of basic sites increase when promoter Li is added, whereas the amount of basic sites decreases when Ce is added. It is found that there are three kinds of basic sites with different intensity on the catalyst surface. On sample Pd/Al2O3 and Pd/Al2O3-Li2O, large amount of CO desorption species is detected, this shows some CO2 on the surface being decomposed. There is no such effect on the sample Pd/Al2O3-CeO2. After analyzing the TPD profiles of NO adsorption on catalysts, it is found that both the NO desorption amount and the shapes of desorption peaks change remarkably when promoter Li or Ce is added. In the case of Li, the γ-peak （nitrate and nitrite species on surface） of NO desorption increases, the intermediate N2O desorbs at higher temperature. In the case of Ce, the α-peak （species on the Bronstesd acidic sites ） of NO desorption decreases, and N2O desorbs at lower temperature.展开更多
文摘采用共沉淀法制备了Ce0.65Zr0.35O2(CZ)储氧材料,分别以乙醇-水、丙醇-水、乙二醇-水、丙三醇-水体系对沉淀物进行陈化,研究了醇的种类对CZ及其负载的单Pd催化剂性能的影响。对CZ进行了扫描电镜(SEM),N2-吸脱附分析,对Pd/CZ进行了粉末X射线衍射(XRD)、X射线光电子能谱(XPS)、储氧量(OSC)和程序升温还原(H2-TPR)的表征,并考察了三效催化性能。结果表明,醇的种类对CZ及Pd/CZ的性能有显著影响。在乙醇–水和丙醇–水陈化体系中制备的CZ分散性高,颗粒堆积松散,比表面积和孔径大,孔容高,且具有优异的热稳定性,其中丙醇–水陈化体系中制备的CZ老化后比表面积和孔容分别可达28 m2/g和0.1 m L/g,具有最高的热稳定性,其负载的单Pd催化剂在老化后对C3H8、CO和NO转化显著优于乙二醇–水和丙三醇–水陈化体系中制备的CZ所制备的催化剂。
文摘The adsorption of CO2 and NO on supported Pd catalysts has been studied by using TPD-MS method and the adsorbed surface species were discussed based on literatures. The amount and intensity of basic sites increase when promoter Li is added, whereas the amount of basic sites decreases when Ce is added. It is found that there are three kinds of basic sites with different intensity on the catalyst surface. On sample Pd/Al2O3 and Pd/Al2O3-Li2O, large amount of CO desorption species is detected, this shows some CO2 on the surface being decomposed. There is no such effect on the sample Pd/Al2O3-CeO2. After analyzing the TPD profiles of NO adsorption on catalysts, it is found that both the NO desorption amount and the shapes of desorption peaks change remarkably when promoter Li or Ce is added. In the case of Li, the γ-peak （nitrate and nitrite species on surface） of NO desorption increases, the intermediate N2O desorbs at higher temperature. In the case of Ce, the α-peak （species on the Bronstesd acidic sites ） of NO desorption decreases, and N2O desorbs at lower temperature.
