催化学报

催化学报 ›› 2011, Vol. 32 ›› Issue (3): 502-507.DOI: 10.3724/SP.J.1088.2011.01122

• 研究论文 • 上一篇    下一篇

BaO 含量对 Ba 改性 Al2O3 及其负载的 Pt-Rh 密偶催化剂性能的影响

姚艳玲, 何胜楠, 史忠华, 龚茂初, 陈耀强   

  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
  • 收稿日期:2010-11-09 修回日期:2010-12-30 出版日期:2011-03-04 发布日期:2014-08-01

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

YAO Yanling, HE Shengnan, SHI Zhonghua, GONG Maochu, CHEN Yaoqiang*   

  1. Key Laboratory of Green Chemistry and Technology of Ministry of Education, College of Chemistry, Sichuan University, Chengdu 610064, Sichuan, China
  • Received:2010-11-09 Revised:2010-12-30 Online:2011-03-04 Published:2014-08-01

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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 1273 K 焙烧 5 h 后, 其比表面积和孔体积分别为 142 m2/g 和 0.45 ml/g; 于 1373 K 焙烧 5 h 后分别为 114 m2/g 和 0.37 ml/g. 以 Ba-Al2O3 材料为载体, 采用浸渍法制备了 Pt-Rh 含量为 1.5 g/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 557 K.

关键词: 氧化铝, 氧化钡, 铂, 铑, 密偶催化剂, 热稳定性, 丙烷

Abstract: In order to improve catalytic activity and thermal resistance of close-coupled catalysts, Ba-modified alumina (Ba-Al2O3) with different BaO contents was prepared by 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-Al2O3 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 ml/g after calcination at 1273 K for 5 h and 114 m2/g and 0.37 ml/g after calcination at 1373 K for 5 h, respectively. Pt-Rh close-coupled catalysts supported on Ba-Al2O3 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 catalytst 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.

Key words: alumina, barium oxide, platinum, rhodium, close-coupled catalyst, thermal stability, propane