Cr-Ag/γ-Al_2O_3催化剂表面氧性质及氧化活性

用等量浸渍法制备了一系列Ｃｒ－Ａｇ／γ－Ａｌ２Ｏ３及其单金属氧化物催化剂，用ＢＥＴ、ＸＲＤ、ＴＰＤ－ＭＳ及ＣＯ氧化反应等，考察了助剂Ａｇ对催化剂表面氧性质及氧化活性的影响。结果表明，单组份Ａｇ／γ－Ａｌ２Ｏ３催化剂的氧化活性随Ａｇ负载量的增加而迅速提高。Ｃｒ／γ－Ａｌ２Ｏ３的氧化活性较差，但添加少量Ａｇ可明显提高其氧化活性，且随Ａｇ添加量的增加而增强。ＴＰＤ－ＭＳ实验发现，Ａｇ的添加明显改变了催化剂的氧吸脱附性能，增强了催化剂供氧和氧恢复的能力，与ＣＯ氧化活性有良好的对应关系。

Surface Oxygen Property and Oxidation Activity of Cr Ag/γ Al 2O 3 Catalysts

A series of the γ Al 2O 3 supported Cr Ag bimetallic and individual mono metallic catalysts were prepared by wetness impregnation method.The oxidation activity of CO was determined in a flow reactor system.The effect of promoter Ag on surface oxygen property and oxidation activity of Cr/γ Al 2O 3 catalyst was studied by BET,XRD and TPD MS.As a result,the temperature of 100% conversion of CO over Ag/γ Al 2O 3 catalysts decreased rapidly as the silver loading increased.The activity of Cr/γ Al 2O 3 catalyst for CO oxidation was relatively poor,however,it was evidently enhanced with the addition of Ag,and increased with increasing content of Ag.The result of TPD MS showed that Ag could obviously promote activity of surface oxygen of the catalyst.CO oxidation activity of the catalysts was correlated to their surface oxygen property.