铜、锰氧化物的表面过剩氧及其甲苯催化燃烧活性

SURFACE OXYGEN PHASE STRUCTURE OF COPPER AND MANGANESE OXIDES AND THEIR ACTIVITY IN CATALYTIC COMBUSTION

研究了负载型Ｃｕ－Ｍｎ－Ｏ催化剂对烃类深度氧化的活性，并将ＸＲＤ分析、电子探针考察和表面过剩氧浓度的分布测定等结果与催化剂活性进行了关联．以甲苯催化燃烧为模型反应，除用常规的微反考察其动力学性质外，还用脉冲反应技术研究了表面过剩氧的氧化功能和甲苯的吸附等．Ｍｎ／Ｃｕ原子比为０．８８～０．９时，催化剂活性最好．这是由ＣｕＯ和ＣｕＭｎ２Ｏ４的功能匹配决定的，后者提供与催化作用有关的表面过剩氧，前者促进甲苯的吸附．对催化剂的作用机理也进行了初步的探讨．

Activity of supported Cd-Mn-O catalysts for hydrocarbon oxidization has been studied.By the determination of surface oxygen,X-ray diffraction,electron-scanning microscopy,Cu-Mn-O catalysts are examined.Taking the toluene combustion as a model reaction, the kinetic behavior of the catalysts is determined in a micro-reactor in steady state and the pulse-reactor-chromatogram technology is used to investigate the oxidation function of surface oxygen and toluene adsorption.It is found that the catalytic combustion activity has close relation with surface oxygen concentratiorl of catalyst and toluene adsorption.It is shown by crystal analysis that there are Cuo phase and CuMn2O4 phase in the catalysts.CuO plays the role of promoting toluene adsorption and CuMn2O4.provides surface oxygen for the catalytic oxidation.The appropriate coupling of the roles of CuO and CuMn2O4 judges the optimum ratio of Mn and Cu is 0. 88 to 0. 90. Based on these results,the activity of the mixture catalysts and the catalytic reaction cycle are discussed.