【摘要】 针对挥发性有机物污染日益严重问题,本文采用水热法制备了纳米棒二氧化铈,并以其为载体,通过浸渍法制备了不同前驱体的Pd/CeO2催化剂。采用透射电子显微镜、X射线衍射、X射线光电子能谱和氢气程序升温还原等手段对催化剂进行了表征,并在微型固定床反应器上评价了催化剂催化甲苯的燃烧性能。结果表明:在采用不同前驱体制备的Pd/CeO2催化剂中,Pd均以Pd2+的形式存在于纳米棒状CeO2表面;在以硝酸钯和氯化钯为前驱体的Pd/CeO2催化剂中,前者具有更低的氢气还原温度,同时在甲苯催化燃烧反应中显示出更低的t50和t90,分别为219和236℃。结果表明,以硝酸钯为前驱体的催化剂具有更高的催化活性。更多还原

【Abstract】 For the problem of volatile organic compounds pollution increasing seriously,palladium catalysts with various precursors supported on CeO2 nanorods were prepared by impregnation method.These catalysts were characterized using transmission electron microscopy(TEM),X-ray diffraction(XRD),X-ray photoelectron spectroscopy(XPS)and H2 temperature programmed reduction.The catalytic performance of these catalysts for toluene combustion was evaluated in a fixed-bed microreactor.The results show that palladium highly dispersed on the CeO2 nanorods surface as Pd2+states in all the Pd/CeO2 catalysts with various precursors.Pd-N/CeO2(palladium nitrate as precursor)shows a lower reduction temperature than that of Pd-C/CeO2(palladium chloride as precursor),and show a lower t50 and t90at 219 and 236℃,respectively,in toluene catalytic combustion,indicating that Pd-N/CeO2 possesses higher catalytic activity than that over Pd-C/CeO2.更多还原