SO2对Pd掺杂La0.9Sr0.1MnO3催化剂去除NOx和碳烟的影响

采用柠檬酸络合法制备了掺杂贵金属Pd的La_0.9Sr_0.1Mn_0.03Pd_0.97O₃钙钛矿型催化剂，并通过X射线衍射光谱及暂态响应、扫描电子显微镜、傅立叶变换红外光谱及程序升温等技术研究了Pd对钙钛矿形貌结构和NOx转化率的影响以及SO₂对La_0.9Sr_0.1Mn_0.97Pd_0.03O₃催化剂脱除NOx的作用机制.结果显示，Pd的成功掺入增大了原催化剂的比表面积，使得催化剂中的活性组分与NOx能够反应的更加充分，有效提高了催化剂对NO的转化率.催化剂La_0.9Sr_0.1Mn_0.97Pd_0.03O₃在含SO₂气氛下反应后出现了微弱的硫酸盐相，说明硫使催化剂发生了一定程度的钝化.在较低浓度SO₂存在时催化剂对NO的转化效率维持在80%以上，碳烟的起燃温度为353℃，但随着SO₂浓度的增加NO的转化效率最高只有67%，碳烟的起燃温度升高到368℃.

Effect of SO2 on the simultaneous removal performance of diesel soot and NOx over Pd doped La0.9Sr0.1MnO3 perovskite type catalysts

The perovskite catalyst La_0.9Sr_0.1Mn_0.03Pd_0.97O₃ doped with noble metal Pd was prepared by citrate method. The effects of noble metal Pd dopant on the morphology structure of perovskite and the NO_{x conversion, and the mechanism of SO2 on the NOx removal performance of La0.9Sr0.1Mn0.97Pd0.03O3 catalyst was investigated in this paper using X-ray diffraction, scanning electron microscopy, Fourier transform infrared spectroscopy, and the transient response method. Results show that incorporating the noble metal Pd into the catalyst increased the specific surface area of the original catalyst, created a suitable place for NO contact, and improved the NO conversion of the catalyst effectively. The catalyst La0.9Sr0.1Mn0.97Pd0.03O3 has a weak sulfate phase after reacting in an SO2 atmosphere, indicating that sulfur resulted in a certain degree deactivation to the catalyst. The conversion efficiency of NOx was maintained above 80% and the temperatures of soot combustion is 353℃ in the presence of a lower concentration of SO2. When the concentration of SO2 increased, the temperatures of soot combustion increased to 368℃ and the conversion efficiency of NOx was only at 67%.}