【摘要】 采用共沉淀法分别制备CeO₂-ZrO₂（质量比60:40）和CeO₂-ZrO₂-La₂O₃（质量比60:30:10）催化剂.利用热重-差热分析（TG-DTA）对柴油车尾气中可溶性有机物（SOF）的催化活性进行测试.结果表明La改性的CeO₂-ZrO₂催化剂相较于CeO₂-ZrO₂催化剂表现出更好的活性,SOF的起燃温度为164℃,最大失重点温度为212℃;对CeO₂-ZrO₂来说,SOF在168℃开始转化,221℃转化最快.X射线衍射（XRD）结果表明,La的添加有效降低老化催化剂的晶粒尺寸增大速率.N₂吸附-脱附的结果说明La的添加有利于增大CeO₂-ZrO₂催化剂的比表面积;O₂-程序升温脱附（O₂-TPD）和X射线光电子能谱（XPS）结果表明La的改性有效增加化学吸附氧含量因此,CeO₂-ZrO₂-La₂O₃催化剂表现出较好的催化活性和抗老化性.更多还原

【Abstract】 CeO₂-ZrO₂ and CeO₂-ZrO₂-La₂O₃ catalysts with mass ratios of 60:40 and 60:30:10 were prepared by co-precipitation method,respectively.The catalytic activity in oxidation of the soluble organic fraction（SOF） in diesel exhausts was studied using thermogravimetric-differential thermal analysis（TGDTA）.The results indicate that the catalytic activity of the La-modified CeO₂-ZrO₂ catalyst is better than that of the CeO₂-ZrO₂ catalyst;the light-off temperature of SOF is 164 ℃,and the weightlessness fastest point temperature is 212 ℃,whereas for CeO₂-ZrO₂,these temperatures are 168 and 221 ℃,respectively.X-ray diffraction（XRD） shows that modification with La is beneficial to decrease the growth rate of the crystallite size relative to that of CeO₂-ZrO₂ after high-temperature ageing.N₂ adsorption-desorption results suggest that the addition of La enlarges the surface area.O₂-temperature-programmed desorption（O₂-TPD） and X-ray photoelectron spectroscopy（XPS） show that modification with La increases the amount of chemisorbed oxygen on the CeO₂-ZrO₂ catalyst.The CeO₂-ZrO₂-La₂O₃ catalyst shows better activity and ageing resistance than the CeO₂-ZrO₂ catalyst.更多还原