Influence of Additives Ceria and Lanthana on Performance of Pd/Al/Monolith Honeycomb Catalysts  

作　　者：田东旭 王浩静 王心葵 

机构地区：[1]Shanxi Institute of Coal Chemistry, Chinese Academy of Sciences

出　　处：《Journal of Rare Earths》2003年第5期529-532,共4页稀土学报（英文版）

基　　金：ProjectsupportedbyScienceandTechnologyCouncilofShanxiProvince ( 982 117)

摘　　要：The effects of ceria and lanthana additives on activity and thermal stabilization of the catalysts for CO oxidation were studied. The results show that the addition of CeO 2 clearly improves the catalytic activity, which may derive from the synergic effect between CeO 2 and PdO. The catalysts were characterized by means of temperature programmed reduction and X ray photoelectron spectroscopy (XPS) measurements. The XPS results of a slight increase in metal oxidation state reflect that the charge transfers from metal to ceria and ceria is slightly reduced, which leads to a decrease of the Ce O bond strength. Pd Ce synergism affects the reduction behavior of the catalysts. The TPR results show that the CeO 2 addition lowers the reduction temperature of PdO, while palladium facilitates the reduction of the ceria. For PdO/La 2O 3/Al 2O 3/monolith honeycomb catalysts, the aging test measurements at 1050 ℃ and the XRD results show that the formation of LaAlO 3 which neutralizes the surface alumina defects inhibits the sintering of alumina.The effects of ceria and lanthana additives on activity and thermal stabilization of the catalysts for CO oxidation were studied. The results show that the addition of CeO 2 clearly improves the catalytic activity, which may derive from the synergic effect between CeO 2 and PdO. The catalysts were characterized by means of temperature programmed reduction and X ray photoelectron spectroscopy (XPS) measurements. The XPS results of a slight increase in metal oxidation state reflect that the charge transfers from metal to ceria and ceria is slightly reduced, which leads to a decrease of the Ce O bond strength. Pd Ce synergism affects the reduction behavior of the catalysts. The TPR results show that the CeO 2 addition lowers the reduction temperature of PdO, while palladium facilitates the reduction of the ceria. For PdO/La 2O 3/Al 2O 3/monolith honeycomb catalysts, the aging test measurements at 1050 ℃ and the XRD results show that the formation of LaAlO 3 which neutralizes the surface alumina defects inhibits the sintering of alumina.

关 键 词：catalitic chemistry CERIA LANTHANA H  2  TPR rare earths 

分 类 号：O643.3[理学—物理化学]