担载铕催化剂氢还原的穆斯堡尔谱研究

IN SITU MOSSBAUER SPECTROSCOPIC STUDY OF HYDROGEN REDUCTION OF SUPPORTED EUROPIUM CATALYSTS

使用原位穆斯堡尔诺考察了γ－Ａｌ２Ｏ３，ＳｉＯ２，ＴｉＯ２和ＺｒＯ２等几种载体担载的氧化铕催化剂的还原性．非担载ＥＵ２Ｏ３很难在Ｈ２中还原，而Ｅｕ２Ｏ３，与γ－Ａｌ２Ｏ３、ＳｉＯ２和ＴｉＯ２间存在着强相互作用，担载在这些载体上的Ｅｕ２Ｏ３，在７７３Ｋ左右Ｈ２中处理可有不同程度的还原，其还原度反映了相互作用的强弱，顺序为：Ｅｕ／γ－Ａｌ２Ｏ３＞Ｅｕ／ＴｉＯ２＞Ｅｕ／ＳｉＯ２＞Ｅｕ／ＺｒＯ２，Ｅｕ／ＺｒＯ２不能在７７３Ｋ还原，表明了Ｅｕ２Ｏ３与ＺｒＯ２间较弱的相互作用．

n situ Mossbauer speroscopy was used. to investigate the reduction behavior of some support such as γ-Al2O3, SiO2, TiO2 and ZrO2 supported curopium catalysts. Europium is an active clement and thus the unsupported Eu2O3 is hard to reduce in H2. However the strong interaction between Eu2O3 and γ-Al2O3, SiO2 and TiO2 facilitates the reduction of Eu2O3.The Eu2O3 supported on these supports can be reduced in H2 at about 773K. The reduction degree can be taken as the cxtent of imeractions between Eu2O3 and the supportS. It was found that the reduction degree follow the series as:Eu / γ-Al2O3 D3> Eu / TiO2 > Eu / SiO2 > Eu / Zro2Eu / ZrO2 catalysts can not be reduced in H2 at 773K, which indicates that the.intoraction between Eu2O3 and ZrO2 is weak.