Performance of soot combustion over CeO2 modified CuO catalysts supported on nickel foams
CeO2-modified CuO catalyst(x CeO2-CuO/NF)was successfully synthesized by hydrothermal method through pre-deposition of CeO2 crystal nuclei on nickel foam substrate.The soot oxidation activity of x CeO2-CuO/NF was significantly higher than that of the catalyst without addition of CeO2(CuO/NF).With the increase of CeO2 content,the Ce/Cu mass ratio and the intrinsic catalytic activity of the catalyst gradually increased,and finally both of them reached stable.Among them,the catalytic activity of 6.5CeO2-CuO/NF was the best with the lowest T50(383℃),which was 32℃lower than that of the CuO/NF catalyst.The results indicate that the pre-deposition of CeO2 crystal nuclei can promote the growth of CuO into a nanostructure,which improves the contact efficiency between soot particles and active sites of the catalyst,on the other hand,the formation of CuxCe1-xO solid solution on x CeO2-CuO/NF enhances the interaction between Ce and Cu cations.The interaction generates a redox coupling cycle between Ce3+/Ce4+ and Cu2+/Cu+,prompting the generation and intrinsic activity of active oxygen species.All of these merits greatly improve the catalytic performance of soot oxidation over our as-synthesized catalysts.
catalystsolid solutionnanostructuremultiphase reactionactive oxygen species
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