Si-Al催化剂对碳烟氧化特性影响的XPS分析

摘要

X-ray photoelectron spectroscopy (XPS) analysis was used to investigate effects of catalyst on soot oxidation characteristics, existing form and differences of soot and partialy oxidized soot were examined. Printex-U (PU) was used to surrogate engine soot, soot became more and more ordered crystaline structure with the temperature increasing with no catalyst added. Soot added catalyst appeared similar oxidation mechanism as wel as the microstructure with ifnish oxidation at 650℃. However, soot appeared lesser ordered crystaline structure under high oxidation temperature of 1000℃. The results show that Si-Al catalyst changes the soot oxidation mechanism under oxygen atmosphere, catalyst with ifnish oxidation at 1 000℃promotes oxidation of ordered crystaline structure which was dififcult to be oxidized.%为揭示Si-Al催化剂对碳烟氧化特性的影响作用，对碳烟及其部分被氧化碳烟的表面结构特征进行X射线光电子能谱(XPS)分析，了解碳、氧元素的表面结构中的存在形态及其差异。以商业碳黑(PU)代替实际的柴油机碳烟，碳烟中不加入催化剂，随着氧化温度的上升，碳烟微观结构的晶格化程度越来越深。加入催化剂后，650℃下碳烟的氧化特性与不加催化剂的相似，微观结构呈现较多的晶格结构。1000℃下碳烟的微观结构中呈现出较多的无序的无定型结构。可知：Si-Al催化剂改变了碳烟在氧气气氛下的氧化机理；1000℃下催化剂的加入，会促进难以氧化的晶格结构的氧化。