Ce_(0.1+x)Ti_(0.5-x)Al_(0.2)Y_(0.1)La_(0.1)O_(1.8)材料的制备及在三效催化剂中的应用  

Preparation of Ce_(0.1+x)Ti_(0.5-x)Al_(0.2)Y_(0.1)La_(0.1)O_(1.8) and Its Application in Three-way Catalyst

作　　者：王康才[1] 刘志敏[1] 王健礼[1] 蔡黎[1] 陈耀强[1] 龚茂初[1] 

机构地区：[1]四川大学化学学院绿色化学与技术教育部重点实验室,成都610064

出　　处：《高等学校化学学报》2009年第8期1625-1630,共6页Chemical Journal of Chinese Universities

基　　金：国家"八六三"计划(批准号:2006AA062347);国家自然科学基金(批准号:20773090)资助

摘　　要：采用共沉淀法制备了Ce0.1+xTi0.5-xA l0.2Y0.1La0.1O1.8(0≤x≤0.4)材料,并对所制备的材料进行了X射线衍射(XRD)和X射线光电子能谱(XPS)的表征,测定了材料的比表面积(BET法)和储氧量(OSC),同时采用氢气程序升温还原(H2-TPR)和氨气程序升温脱附(NH3-TPD)研究了材料的还原性能和表面酸性.研究结果表明,Ce/Ti摩尔比大于1∶2的材料能形成立方萤石结构的固溶体,Ce/Ti摩尔比为1时,材料表面Ce4+/Ce3+摩尔比达到最大;随着Ce/Ti摩尔比的增大,材料的储氧能力先增大后减小,而TPR还原峰温则是先减小后增大,当Ce/Ti摩尔比为1时,材料的储氧量达到最大,为660μmol/g;还原峰峰温最低,为616℃.以制备的材料为载体制备了一系列Pt/Ce0.1+xTi0.5-xA l0.2Y0.1La0.1O1.8三效催化剂,并对催化剂进行了活性评价.活性测试结果表明,以Ce/Ti比为1的载体材料制成的催化剂对C3H8,CO和NO的起燃温度分别为236,147和228℃,表现出了优异的温度特性.Ce0.1＋xTi0.5-xAl0.2Y0.1La0.1O1.8 （0≤x≤0.4） mixed oxides were prepared by co-precipitation method and characterized by means of X-ray diffraction （XRD）, X-ray photoelectron spectroscopy （XPS）, nitrogen adsorption（BET） , oxygen storage capacity（OSC） , H2-temperature programmed reduction（ H2-TPR） and NH3-temperature programmed desorption （NH3-TPD）. The results of XRD revealed that there was only one single cubic phase in Ce0.1＋xTi0.5-xAl0.2Y0.1La0.1O1.8 system when x value increased from 0. 2 to 0. 4. The results of XPS showed that the ratio of superficial Ce^4＋/Ce^3＋ is maximal when x is 0. 2. With the increase of Ce/Ti ratio, OSC is increased to a maximum value, and then gradually decreased. When x value is 0. 2, the OSC reaches to 660 umol/g, and the reduction temperature of Ce^4＋ is the lowest according to the H2-TPR test （616℃ ）. In this paper, a series of Pt/Ce0.1＋xTi0.5-xAl0.2Y0.1La0.1O1.8 three-way catalysts were prepared and the catalytic activities of catalysts were investigated. The results revealed that Pt/Ce0.3 Ti0.3Al0.2Y0.1La0.1O1.8 exhibits excellent low-temperature catalytic activity. The light-off temperature of C3 H8, CO and NO over Pt/ Pt/Ce0.3 Ti0.3Al0.2Y0.1La0.1O1.8 is 236, 147 and 228℃, respectively.

关 键 词：Ce0.1+xTi0.5-xAl0.2Y0.1La0.1O1.8 Ce/Ti摩尔比 载体材料 三效催化剂 

分 类 号：O643[理学—物理化学]