Study On Preparation Of Au Catalysts Supported On Pillaring Bentonite And CNTs And Their Catalytic Performance

The high activity of Au catalyst with high dispersion of gold particles forlow-temperature CO oxidation has caught more and more people’s attention. Sincethe confinement effect of carbon nanotubes is found and posed by academician Bao,people’s research has gone into a new chapter of Au catalysts confined by carbonnanotubes. In this paper, carbon nanotubes were modified by different methods andsupported by different active substance. Then the catalysts were detected by COoxidation and characterized by XRD、BET and IR. It can be seen from the results thatAu-Fe composite component supported on KOH-modified carbon nantotubes hadmuch higher activity than supported on the acid-modified and purified carbonnanotubes. The characterization results also indicated that graphitization degree ofKOH-modified carbon nanotubes reduced greatly than aci-modified or purifiedcarbon nanotubes. Thus, its surface defects increased and surface area increacegreatly correspondingly. At present, active supports (e.g. Fe2O3, TiO2, CeO2) aremostly used to support Au catalysts traditionally. It’s rarely to notice that bentonite asa support thing. Bentonite has a unique one-demension layered structure which canconfined the active componet nanostructures into its layers, in case of controlling thesize of Au and increasing dispersion to gain higher activity as expect. In this paper, Fewas used as active component and Al as dispersion component to get the bentonitepillared. Then Au catalysts were prepared by deposition-precipitation method anddetected by CO oxidation and characterized by XRD, BET and IR. As can be seenfrom the results that the interlayer of bentonite might have been strutted apart so thatAu nanopaticles confined into the strcture of the interlayer. Thus, we can obtain Aucatalysts prepared by Au nanoparticles with fine dispersion and smaller size cofinedby bentonite.