| CeO2 can not only enhance the catalytic activity of catalysts,but also can improve the thermal stability of catalysts.Scientists want to use it as support of catalyst directly.However,their small surface area(generally less than 10 m2/g)and poor mechanical strength make it difficulty to be applicated as support of catalyst successfully.In this paper a serias of supported nano-CeO2 composite supports were prepared.γ-Al2O3 was acted as base support and nano-CeO2 was acted as functional support,which will make CeO2 disperse on the surface ofγ-Al2O3 evenly.Therefore, CeO2 will have large surface area,better mechanical strength and good thermal stability.The properties of composite support were characterized by the XRD,DTA, BET(N2 adsorption),TPR and TPD technology.Results show that in process of preparation,vacuum soaking and microwave drying can reduce the size of CeO2 particle which loaded on the the composite supports,thus changing the surface area of support;When the CeO2 was loaded less than 20 percent,nano-CeO2 was dispersed on theγ-Al2O3 surface monolayer.With the CeO2 content increasing,the CeO2 particles were dispersed on the surface ofγ-Al2O3 more fully.However,as the CeO2 content was greater than 30 percent,the nano-CeO2 loaded on surfacedγ-Al2O3 showed a multi-layer dispersion.The calcination temperature of samples we accepted is 450℃, When the calcination temperature goes to 500℃or higher,the nano-CeO2 particle and based supportγ-Al2O3 will form a composite oxide or melt each other,which will affect the performance of composite supports.Then,the catalytic activity of catalysts was studied throught the Catalytic oxidation of CO,results showed that catalytic activity of CuO/CeO2/Al2O3 catalyst is better than that of CuO/CeO2 catalyst.Compared with pure CeO2 cartier,supported nano-CeO2 composite support had larger surface area,better thermal stability and mechanical strength,which will improve practical application of catalyst.
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