铈和镧改性γ-Al_2O_3担载Pd催化剂的结构效应  

The Structural Effect of CeO2 and La2O3 Modified Pd/γ-Al_2O_3 Catalysts

作　　者：杨成[1] 董庆年[1] 张静[2] 任杰[1] 孙予罕[1] 谢亚宁[2] 胡天斗[2] 

机构地区：[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 [2]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

出　　处：《物理化学学报》2002年第2期170-174,共5页Acta Physico-Chimica Sinica

基　　金：国家杰出青年基金(974609);山西省青年基金(991010)资助项目~~

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.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.

关 键 词：氧化铈 氧化镧 结构效应 甲醇 分解 Γ-AL2O3 氧化铝 改性 负载型钯催化剂 催化活性 助剂 

分 类 号：O643.3[理学—物理化学]