Study Of Catalytic Performance CO Oxidation On Au Or Pd Supported On Ceria Nanotubes Catalysts

As an important rare earth functional material,ceria is widely used as a catalyst because of its oxygen deficiency,strong ability to store and release oxygen and easy conversion of Ce³⁺and Ce⁴⁺.Carbon monoxide catalytic oxidation widely used in gas sensing,automobile exhaust and fuel cells.Catalysts frequently used for the catalytic oxidation of carbon monoxide include metals such as platinum,gold,palladium,and copper and so on.The bulk of precious metal is chemically inert,when its particle size becomes nanometers that exhibits an remarkable catalytic effect for carbon monoxide oxidation.Various morphologies of ceria nanomaterials used as catalytic carrier to support precious metals for carbon monoxide oxidation showed good catalytic effect.The ceria nanotubes supported noble metal catalysts for carbon monoxide oxidation the effect is outstanding.In this paper,CeO₂nanotubes were selected as carriers to support noble metal gold and palladium nanoparticle catalysts to study their catalytic properties for CO oxidation.Meanwhile,studying the effect of catalytic activity for Pd catalysts under the different reduction temperatures.The specific research contents are as follows.1.Using the hydrothermal method synthesis of CeO₂ nanotubes,nanorods and nanocubes,chemical reduction method to prepare gold nanoparticles,incipient wetness impregnation method to achieve the gold nanoparticles in the ceria nanomaterial loaded.CO oxidation as a probe reaction.The effect of CO oxidation on the catalytic activity of different ceria nanomaterials was investigated.It was found that the catalytic effect of the CeO₂ nanotubes supported Au catalyst was the best.The Ce O₂ nanotubes,nanorods and nanocubics of lattice plane was characterized by BET,H₂-TPR,XPS,TEM and so on.The effcct of gold and various crystal faces was different.Au/CeO₂NT catalyst contains more Ce³⁺and Au⁺so the catalytic performance of the CO oxidation is best.2.The Pd/CeO₂NT catalyst was prepared by the incipient wetness impregnation method using palladium oxide nanoparticles as active ingredient supported on CeO₂ nanotubes.Using hydrogen as a reducing gas,the catalyst was reduced at 150?,250? and 350? for two hours.Comparative study the effect of different reduction temperatures for CO oxidation.The study results found that the catalyst which is reduced at 350?has the best catalytic activity for CO oxidation,and the complete oxidation of CO at 70?.It was found by XRD,BET,H₂-TPR,XPS,TEM and other characterization methods proved the catalyst had the most Ce³⁺and Pd⁰ on the surface at 350?reduced two hours.