物理化学学报 >> 2002, Vol. 18 >> Issue (02): 170-174.doi: 10.3866/PKU.WHXB20020216

研究简报 上一篇    下一篇

铈和镧改性γ-Al2O3担载Pd催化剂的结构效应

杨成;董庆年;张静;任杰;孙予罕;谢亚宁;胡天斗   

  1. 中国科学院山西煤碳化学研究所 煤转化国家重点实验室,太原 030001;中国科学院高能物理研究所 同步辐射国家重点实验室,北京 100039
  • 收稿日期:2001-06-25 修回日期:2001-10-09 发布日期:2002-02-15
  • 通讯作者: 孙予罕 E-mail:yhsun@sxicc.ac.cn

The Structural Effect of CeO2 and La2O3 Modified Pd/γ-Al2O3 Catalysts

Yang Cheng;Dong Qing-Nian;Zhang Jing;Ren Jie;Sun Yu-Han;Xie Ya-Ning;Hu Tian-Dou   

  1. The State Key Laboratory of Coal Conversion,Institute of Coal Chemistry,Chinese Academy of Sciences,Taiyuan 030001;The State Key Laboratory of Synchrotron Radiation,Institute of High Energy Physics,Chinese Academy of Sciences,Beijing 100039
  • Received:2001-06-25 Revised:2001-10-09 Published:2002-02-15
  • Contact: Sun Yu-Han E-mail:yhsun@sxicc.ac.cn

摘要: 分别以镧-铈、铈-镧顺序浸渍和镧铈共浸渍的方式在γ-Al2O3载体上引入助剂La2O3和CeO2,然后担载Pd制备了一系列催化剂.以甲醇分解为探针反应,采用XRD、EXAFS和XPS对催化剂的体相和表面结构进行表征,用BET法测定比表面积,并进行了吸附态CO的FTIR研究.结果表明,La2O3容易进入CeO2的晶格中,促进了CeO2在γ-Al2O3上的分散.但不同的La2O3、CeO2加入方式对活性组分Pd在改性载体上的分散度、优势暴露面及其与CeO2之间的相互作用产生不同的影响.关联甲醇分解性能测试结果说明,Pd在载体上的高度分散以及Pd和CeO2之间通过界面产生的强相互作用是催化剂具有高活性的关键.

关键词: 氧化铈, 氧化镧, 担载Pd, 结构效应, 甲醇分解

Abstract: A series of Pd/γ-Al2O3 catalysts modified by CeO2 and La2O3 were prepared by impregnation method with different La2O3,CeO2 dope manners.Methanol decomposition was used as a probe reaction.The structure of the catalysts was characterized by means of BET,XRD,XPS and FTIR.The results showed that a La2O3 -CeO2 solid solution was facile to form by La3+ dissolution into CeO2 lattice.The dimension of CeO2 particles decreased,while the dispersion and crystal plane of Pd and the Pd-CeO2 interaction varied with La2O3,CeO2 dope manners.High dispersion of Pd and a strong interaction between Pd and CeO2 were observed on a La2O3 and CeO2 modified Pd/Al2O3 catalyst with La2O3-CeO2 successive dope manner,which resulted in high activity for methanol decomposition.

Key words: La2O3, CeO2, Supported Pd, Structure effect, Methanol decomposition