钾掺杂对铈锆固溶体催化性能的影响

为研究钾掺杂对铈锆固溶体催化性能的影响,以Ce0.7Zr0.3O2为基体制备了一系列钾掺杂的铈锆固溶体xK-Ce0.7Zr0.3O2(x=0.05、0.10、0.15、0.20、0.25、0.30)催化剂样品,通过程序升温氧化(TPO)过程进行活性评价,并通过XRD、BET、H2-TPR和O2-TPD进行分析表征。结果表明,采用溶胶凝胶法制备的催化剂的催化性能比络合燃烧法所制备的稍好;当钾的掺杂量为0.10≤x≤0.30时,xK-Ce0.7Zr0.3O2催化碳烟颗粒燃烧的活性得到提高,起燃温度和最大燃烧速率温度分别在315℃和375℃附近,明显优于Ce0.7Zr0.3O2;掺杂钾后的催化剂样品均能形成萤石结构,并且随钾掺杂量的增大比表面积减小。

Influences of doping potassium on catalytic performances of ceria-zirconia solid solutions

A series of xK-Ce0.7Zr0.3O2(x=0.05,0.10,0.15,0.20,0.25,0.30) solid solutions were prepared.The influence of doping potassium on the catalytic performance for particle materials(PM) oxidation was investigated by temperature-programmed oxidation reaction(TPO).And all the catalysts were characterized by the techniques of X-ray diffraction,BET surface area,H2-TPR,and O2-TPD.The results show that the catalytic performance of the catalyst which prepared by sol-gel method is better than by complex-combustion method.The catalytic performances of xK-Ce0.7Zr0.3O2(0.10≤x≤0.30) catalysts are obviously better than Ce0.7Zr0.3O2,whose ignition temperature and maximum soot oxidation rate temperature are around 315℃ and 375℃,respectively.After introduction of potassium,all the catalysts form cubic fluorite structure,and their surface areas decrease with the rise of x value.