氧化物催化剂表面过剩氧与氧化活性

The Amount of surface Excess Oxygen of the Oxide Catalyst and their Oxidation Activity

本文采用肼法测定了金属氧化物催化剂表面过剩氧的浓度，并考察了吡啶的氧化活性。催化剂的氧化活性与表面氧浓度成正比。氧化活性和表面氧浓度的顺序为：Ｃｕ－Ｏ／Ａｌ＿２Ｏ＿３＞Ｍｎ－Ｏ／Ａｌ＿２Ｏ＿３＞Ｃｒ－Ｏ／Ａｌ＿２Ｏ＿３＞Ｆｅ－Ｏ／Ａｌ＿２Ｏ＿３≥Ｃｏ－Ｏ／Ａｌ＿２Ｏ＿３＞Ｎｉ－Ｏ／Ａｌ＿２Ｏ＿３＞Ｃｅ－Ｏ／Ａｌ＿２Ｏ＿３．随着催化剂焙烧温度的提高，催化剂表面氧浓度和氧化活性均下降。Ｃｕ－Ｏ／ＳｉＯ＿２催化剂中添加ＣｅＯ＿２后，催化剂表面氧浓度和氧化活性均有明显提高，同时催化剂的热稳定性也明显增加。

In this paper,the surface oxygen concentration of the metal oxide catalysts was determined by themethod of the hydrazine as reductive agent and the activitv of pyridine oxidation was studied. A good relativi-ty between the catalytic oxidation activity and the excess amount of surface oxygen over the catalyst was ob-served.The oxidation activity of the catalysts is proportional to the excess amount of surface oxygen,Theorder of oxidation activity and surface excess oxygen determined is:As the calcination ternperature rises,the surfaceoxygen concentration and activity of catalysts descendes.The addition of CeO_2 caused an increase in the sur-face oxygen concentration and the oxidation activity,and the thermal stability of Cu-O/Al_2O_3 catalyst.