锆钛复合氧化物的制备及用作Pt三效催化剂载体的性能  

Preparation of Titanium-Zirconium Mixed Oxide and its Catalytic Performance of Pt Three-way Catalysts

作　　者：喻瑶[1] 林涛[1] 张丽娟[1] 郭家秀[1] 龚茂初[1] 陈耀强[1] 

机构地区：[1]四川大学化学学院,成都610064

出　　处：《无机材料学报》2008年第1期71-76,共6页Journal of Inorganic Materials

基　　金：国家自然科学基金(20333030)

摘　　要：用共沉淀法制备了Zr_(0.5)Ti_(0.5)O_2复合氧化物,考察了沉淀时的pH值、温度及焙烧温度对样品织构性能的影响.分别用BET、XRD、NH_3-TPD对样品的织构、结构性能和表面酸性进行了表征.将经过不同温度焙烧后的样品作为载体制备成Pt/Zr_(0.5)Ti_(0.5)O_2催化剂,考察了催化剂对C_3H_8、CO、NO的催化性能,并与传统的以La-Al_2O_3为载体的Pt/La-Al_2O_3汽车尾气三效催化剂进行了比较.结果表明:当沉淀时的pH=11、温度为25℃、焙烧温度为550℃时,所制得的样品具有较好的织构性能(比表面积为195m^2·g^(-1)、孔容为0.28mL·g^(-1))、较强的表面酸性和较宽的酸度分布;用该样品制备的汽车尾气三效催化剂与传统的以La-Al_2O_3作载体的Pt/La-Al_2O_3催化剂相比,具有更好的HC和CO催化性能和优异的NO转化性能.Zr0.5Ti0.5O2 mixed oxides were prepared by co-precipitation method. The effects of pH value, precipitation temperature and calcination temperature of Zr0.5Ti0.5O2 on its specific surface area, pore size, pore volume and surface acidity were investigated. The samples calcined at 500℃, 550℃, 600℃, 650℃, 700℃, 800℃ for 2h, were characterized by means of BET, X-ray diffraction （XRD） and NH3-temperature programmed desorption （NH3-TPD）. Using the Zr0.5Ti0.5O2 and La-Al2O3 as catalyst carriers, and the activities of Pt/Zr0.5Ti0.5O2 and Pt/La-Al2O3 catalysts were evaluated in the simulated gas. The results show that when the pH is 11, precipitation temperature is 25℃, calcination temperature is 550℃, Zr0.5Ti0.5O2 exhibits the highest specific surface area（195m^2·g^-1）, larger pore volume（0.28mL·g^-1）, proper surface acidic amount and acidity. Compared with Pt/La-Al2O3, Pt/Zr0.5Ti0.5O2 exhibits excellent low-temperature catalytic activity and lower the light-off temperature of hydrocarbon （234℃） and carbon monoxide （203℃） and nitrogen oxides （213℃）. At the same time, it is found that the Pt/Zr0.5Ti0.5O2 catalysts significantly improve the conversion for nitrogen oxides.

关 键 词：Zr0.5Ti0.5O2复合氧化物 汽车尾气三效催化剂 性能 

分 类 号：O643[理学—物理化学]