BaO含量对Ba改性Al_2O_3及其负载的Pt-Rh密偶催化剂性能的影响  

Effects of BaO Content on Properties of Ba-Modified Alumina and Catalytic Performance of Its Supported Pt-Rh Close-Coupled Catalysts

作　　者：姚艳玲[1] 何胜楠[1] 史忠华[1] 龚茂初[1] 陈耀强[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,四川成都610064

出　　处：《催化学报》2011年第3期502-507,共6页

基　　金：国家自然科学基金(20773090;20803049);高等学校博士学科点专项科研基金(20070610026)

摘　　要：采用胶溶法制备了不同BaO含量的Ba改性的Al2O3样品(Ba-Al2O3).采用低温N2吸附-脱附、X射线衍射和氨程序升温脱附对样品进行了表征.结果表明,BaO的添加量为8%时,Ba-Al2O3样品具有最佳的织构性质、最大的表面酸量和最强的表面酸性;经1273K焙烧5h后,其比表面积和孔体积分别为142m2/g和0.45ml/g;于1373K焙烧5h后分别为114m2/g和0.37ml/g.以Ba-Al2O3材料为载体,采用浸渍法制备了Pt-Rh含量为1.5g/L的密偶催化剂.催化剂活性测试结果表明,BaO的添加可有效提高催化剂上丙烷的转化活性,且当BaO含量为8%时,催化剂活性最高,新鲜和老化的催化剂上丙烷的起燃温度分别为513和557K.In order to improve catalytic activity and thermal resistance of close-coupled catalysts, Ba-modified alumina （Ba-A1203） with different BaO contents was prepared by the peptization method. All samples were characterized by low temperature N2 adsorption-desorption, X-ray diffraction, and NH3 temperature-programmed desorption. The results showed that the Ba-A1203 sample with 8% BaO exhibited the best textural properties, the largest acidic amount, and the strongest surface acidity. Its specific surface area and pore volume were 142 m2/g and 0.45 mug after calcination at 1273 K for 5 h and 114 m2/g and 0.37 mug after calcination at 1373 K for 5 h, respectively. Pt-Rh close-coupled catalysts supported on Ba-A1203 were prepared by impregnation method with Pt-Rh content of 1.5 g/L. The catalytic activity results showed that adding BaO into the support can effectively improve the catalyst activity in propane conversion. When the BaO content was 8%, the catalyst exhibited the best catalytic performance. The light-off temperatures for propane over fresh and aged catalysts were 513 and 557 K, respectively.

关 键 词：氧化铝 氧化钡 铂 铑 密偶催化剂 热稳定性 丙烷 

分 类 号：O643.36[理学—物理化学]